[Prologue: victorpan]
Here are the rules to participate:

1. Reply to the whole topic to state your stance. One word only.
2. Include ONE argument.
3. Other members can reply to an existing argument with counter arguments, and so forth.
4. Upvote if you agree to an existing argument or counter argument
5. You're allowed to take both sides, but real gentlemen (and women) take turns.

[Verse 1: AJ Kohn]
1. Black
2. Unlike a paywall, the act of sharing is an endorsement to others not an exchange of value between creator and user. Forced endorsements aren't really endorsements but only signals of engagement of a sort, which may or may not reflect true sentiment. So not only do you get very lame evangelism (Tweet and delete) but you dirty your own ability to measure true evangelism.

[Rebuttal 1: victorpan]
1. White
3. Sharewalls have been a staple tactic to spread awareness for social competitions. They have become a norm where users expect to exchange their own word of mouth for the potential of winning a trip to the Maldives. The user is exchanging the value of their social voice for the service provided by the creator.

[Rebuttal 2: AJ Kohn]
1. White rhymes with Shite.
3. So you get a bunch of people to spread the word about this content and then they don't win and then they're still sort of endorsing the site about the Maldives or travel. They haven't endorsed anything really except self-interest. Been there done that in eCommerce - sign-up to get this coupon. Guess what, the vast majority of that list becomes dead wood and you spend more time chasing low margin customers than optimizing high value ones.

TL;DR - it might be white but it doesn't make it a good tactic.

[Side Commentary 1: Clayburn Griffin]
> White rhymes with Shite.
So does right. And blight. And might. And fight. And bright. Now I don't know what to think!
[Verse 2: Paul Shapiro]
1. Black
2. Ok, so I would have said white hat (or maybe grey hat if that were an option), because if remove personalized Google+ results from the picture, forcing people to share on social media really won't directly impact search rankings. I believe Google on this point. Duane Forrester also has indicated an effect from Facebook shares, only in exceptional cases. It probably will indirectly through latently build backlinks, but there is nothing inherently wrong about that in the eyes of the search engines. However, they feel really seedy and are an attempt to manipulate the social space. As a social media tactic, it very much has the feeling of a grey or black hat SEO tactic.

[Side Commentary 2: Paul Shapiro]
I really like how Matthew Woodward handles the sharewall on his blog. Rather than preventing access to his content, the share is used as a payment if you wish to download a PDF version of his posts or download his video content.

[Verse 3: Clayburn Griffin]
1. White (Unless...)
2. I think it's a legitimate ask that people share something to use it. However, if you block off all access unless they share, then you're pushing them to vouch for something they know nothing of. That's black hat. But if instead you have some kind of rate-limiting or extra features for people who evangelize for you, then it's perfectly fine. Also, it can be black hat if you're asking them to share something unrelated or tricking them into sharing something they don't realize they're sharing. Think of yourself as the user. If you'd be screwing yourself, then it's probably black hat.

[Verse 4: Matthew Barby]
1. White
2. If you're interested enough to consume/download the content behind a sharewall then your social share should be seen as a valid endorsement. If this is the case that you want to be entered into a competition, it helps to spread awareness and more social reach for your competition and can be great for traffic generation.

On the flipside of things, the real importance lies within the message being shared. In order to segment this away from other social signals you should be tracking these shares separately. This could be via a competition hashtag or specific text/link within the share.

[Verse 5: Nick Eubanks]
1. Meh
(sorry to break the rules; it's not to be rebellious. But I don't think this is a binary issue, although I understand the utility of drawing a line in the sand)
2. I think this is an extremely subjective, case by case answer. I'm happy to endorse a brand whom I trust and follow to get access to a report or a whitepaper. It is most likely a valid endorsement if I am interested enough to make the share to consume the information. However, this is a very slippery slope when applied in other scenarios, say for example a blog post, where only the first hundred words is displayed as a hook to lure the reader in. A sharewall will force me to endorse the content, the author, and more than anything else, the brand - potentially without any prior exposure to any of the above, and more so I may have just endorsed content that is complete shit, because I had no way of knowing so until afterwards.
::sorry to muck up the rules::

[Verse 6: Vinny La Barbera]
1. White (although I agree with Nick that it's not always one or the other)
2. This practice has been used for years, well before social media. The first example that comes to mind is when many restaurants would have patrons fill out comment cards and their email or shipping address to be entered into a giveaway or raffle. [I actually still see some places do this]. A sharewall is just the online equivalent of this and, in my opinion, a perfectly practical and sometimes creative way to encourage social endorsements. It's not top of mind for most people to share their experiences at certain establishments, even when they're positive. These little nudges can help them to do just that - even if takes a bit of coercing.
[Verse 7: Ed Fry]
1. Neither
I think the 'black vs white' argument seems to be applied to can you game X big website or search engine. 'Black hat' SEO is problematic because search engines exist etc.
What about the feckin' user?
Do I want to share something to my friends and followers I haven't seen yet? It depends.
- Do I know and trust this brand already?
- Do I really, really want what they're offering?
- Would I share it anyway?
- (Most importantly) Does it make me look and feel good to share? (Will friends and followers appreciate it. Really?)
re: the black vs. white argument, I think so long as there's something new, there will exist an area where people can game rules. But the questions above won't. If you're sharewall page is creating behaviour that would happen anyway (i.e. its welcome. Its inbound) then there's no real problem. But if its an unwelcome, interruption that's manipulating the course of behaviour with consequences the user doesn't intend for ("spamming" friends and followers) then yes, there's a problem.
Does this become a problem for search engines/social media sites? Only if the internet is over-run with them, their users avoid them regularly and use their services less. i.e. if sharewalls threaten a search engine or social networks user engagement, policies and algorithms will be formed against them which makes them 'black'.
But if you're having to question a tactic where you're coercing or supporting natural user behaviour, I'd be wary of it. It may deliver great short term wins (perfect if you're in for just one innings), but its not necessarily a stable, sustainable long term strategy.

[Side Commentary 3: Joe Preston]
Aw, come on... "Do I want to share something to my friends and followers I haven't seen yet? It depends."
Does it really depend? If you got to choose, would you ever choose to share content sight unseen?

[Verse 8: Larry Kim]
1. White.
2. Similar thoughts to Matthew Barby here -- that you can't force anyone to share anything. People have free will - people can simply decide not to share the thing. A company has the right to ask for whatever they want to in exchange for their stuff. Case closed (heh).

[Side Commentary 4: Ian Howells]
...except if they want to ask for money in exchange for a link.

[Verse 9: Patrick Coombe]
1. ILLEGAL BLACK HAT - ok just kidding White Hat
2. I am a scientist and have dabbled with / tried everything (except the illegal stuff) and have concluded through years of testing that white hat is the way to go. Furthermore, I work with an agency that is extremely white hat and it would be really hypocritical if I were to lead a dual life.
Lately I am of the philosophy of "hippy marketer." I think a lot of this black hat stuff is just polluting the internet with crap. While some people have shown that these tactics do "work" it is just filling the interwebs up with so many spammy pages it just makes it terrible for UX as a whole.
On the other hand I have always wondered how things worked, so when a new technology comes out I will always try to break it / game it / see if there are any unintended uses, etc.
[Verse 10: Jake Butler]
1. Neither
2. While I would lean more towards it being black, simply because it's a way to manipulate social activity, and we do know that social signals impact rankings at least in some way, Google has never taken an official stance against it as far as I know. It's not really white hat either because it goes over the line of what you could reasonably consider to be organic/natural/earned activity. So I don't think there's an answer until Google says yes this is okay or no stop doing this. And if I've happened to miss Google's officials stance on this sort of thing, someone please correct me with a link.

[Verse 11: Brian Dean]
1. White
2. That being said, I don't think it's a smart long-term strategy.
If your service/content/tool is good enough to be shared naturally, it WILL get shared. Period. End of story.
Do you think Google needed a sharewall in 1998? LOL.
Did Facebook force you to email a friend about it before you could sign up? Nope.
Flash forward to more recent times: does Pinterest make you "tweet" Pinterest before sharing pictures with your friends? Heck no.
Why?
Because they all have services that are worth sharing. They don't need cajoling or arm-twisting to get the word out.

[Side Commentary 5: Yan Desjardins]
WHITE agree with @Brian!

[Verse 12: gareth jax]
1. useless
No way i'm gonna share something unwilingly. I quickly pass from a state of "annoyed" to "pissed" whene there is no "close" button. Since i use chrome, the next step is to "inspect element" and "delete node" related to the wall.
I hope adblock kill them all.

[Verse 13: Ian Howells
1. Black
2. Given the assumption that social will, at some level and some point, be a significant ranking factor - it's no different then forcing people to link to you in order to download something. That would be considered 'blackhat' (vs the Google guidelines) - so why would this be any different? It's still a value exchange (monetary or not - see also: Rap Genius) for something that impacts rankings.

[Side Comentary 6: Paul Shapiro]
Do you think there is such thing as black hat social media marketing? Sharewalls may qualify.

[Verse 14: Tommy Walker]
1. Grey
2. I agree with AJ that you shouldn't have to enforce an endorsement before getting to the good stuff. HOWEVER I think a sharewall is a great idea, if you've already proven your value. Not in your free blog stuff, but through other deeper, more personal content.
I'm not going to get into the specifics of how to do this, because it's a test I'm about to run on ConversionXL but I will say that the way I'm planning on implementing it will increase social sharing, without making people pissed and after they've already gotten something good.

[Verse 15: Samuel Lavoie]
Black.
Looks like social black hat for me as you are forcing endorsements.
But as others said, if there is already proven value, I see it working in ways similar to how you would use a registration form or micro transaction to access extra content.

[Verse 16: Goran Candrlic]
1. Rainbow
2. Depends on the context. Drives interest and little more traffic. If you optimize your KPIs you don't need to worry about focusing on bad customers. AJ is right, but... For example (and I think Unbounce had an A/B test for it) - give users an option - email or share. Simple as that. See what works better. Be pragmatic.