Whatever you all use, (regardless of any copyright concerns) if the text in the documentation is not searchable by the end user then it may not worth be documenting IMO .
I’ve had the honor of being able to give back to some of the fine developers here in a way other than financial support. In fact, just recently one in particular lacked a specific android device for testing which I happened to have. I was happy to help where I could. Plan to do so again whenever needed / I can spare the time.
Hopefully that and / or the name change will translate to the higher sales for you! 
That’s a respectable attitude / stance, MBMedia. No author should be a “replacement” for the provided documentation, faq, item details page, etc. That’s just extremely lazy and/or inconsiderate behavior. Many of the entitled folks probably do know better but simply like seeing what they can getting away with.
They probe boundaries (especially with a author they haven’t dealt with before) like a child does with their parents. Some just never grow out of that phase / habit potentially. I support shutting them down in that instance because that’s abuse AFAIK (especially if it’s pre-purchase).
Take a look at “Private Content” by LCWeb over on CodeCanyon. If it looks like it’ll do what you want, the product and support have both been top notch!
If there’s any confusion, I do agree that there should be little / no expectation of support (regardless of Envato’s official position) due to the relatively low cost of items here. However, I am still often shocked and awed by either the total lack of support vs the abundance received (not the norm, of course). Suffice it to say, I’m likely spoiled (to whatever degree) by certain authors. So, I just thank them profusely and continue to reward them with my business and referrals / recommendations. If that makes me less tolerant of other authors, I apologize but don’t expect that to change.
@MoonWorks – Agreed. However, over here though video is worth a bit more (29.97 fps to be exact). Ha ha.
Your video while interesting doesn’t actually show enough of the product itself. Showing the creation of a small / short facebook app / page from start to finish would be more demonstrative, I think.
I have to admit that I wouldn’t have take a second look at your product unless you posted here. I admit to scanning the title when I first saw and dismissing it outright because it didn’t sound useful in my head. Now that I actually clicked through (which I didn’t do before), I see what it is you’re actually selling. The video should illustrate this even if I don’t read the text which I don’t feel it did well enough.
I think the current title might be doing the product a disservice. Instead of “Facebook Tabs”, why not call it something like – “WordPress Site Embedder for FaceBook”? Unless I misunderstand, isn’t that more accurate a name for your product? I can imagine people seeing the title, watching the video and still wondering why it’s called “Facebook Tabs for WordPress”. I know FB does refer to them as “Page Tabs” but perhaps not everyone knows that? Since your product seems to do more than just create these tabs, does it seem that the current name sounds somewhat limiting? Just my opinion. If it helps you out then great. Whatever you call it, you may wish to consider a name change.
I’ll agree with that if those 20+ people don’t read either the FAQs or Product Details that already contain the needed information. There’s not much that can (legally) be done about people that don’t read / search. However, you can refer them once and hope they learn. The repeat offenders should be dealt with harshly (not really)!
Perhaps a BIG notice in your product details section like the following might suffice?
“Every time a question gets asked in the comments section that’s already in the FAQ this FORCES two kittens to FIGHT to the DEATH with medieval weaponry! Do you want to be responsible for the outcome? Do you?!” – Inspired by Chris of SevenSpark (I take no credit) – Just make sure they know you’re joking because no one needs the animal rights activists knocking at their door. (asterisk / star). LOL .
(asterisk / star) = No kittens were actually harmed during the writing of this post. 
@kotofey – I would say to you much of what I said to duotive in the post above yours. If you’re getting abused by your prospects / customers it may be because you’re potentially enabling / inviting that kind of behavior in certain instances. If not, then consider the following as well…
If I was asked how to create a custom post type, I’d point them to one or more free / paid plugins that do that (there are plenty of no code ways to do this). If it’s a common question, put it in your products details page / faq sections. People that read those may not need to ask such questions then. You could also easily link them them to the WP Codex (or specific page there)? I never like to assume that people know the Codex exists so I suggest it often. It takes very little time to do one or both of these things and more often than not, you may find you’ve just converted a prospect to a customer!
If they still aren’t satisfied with any of that and you’re available for freelance, by all means offer your services. If you’re not available for freelance work, by all means refer them if that’s what they need / want. If they still yet aren’t satisfied then you’ve already been more than reasonable. Otherwise, you may come off as a “lazy developer” (or worse) even if you are not / didn’t intend to present yourself that way. I’m also not trying to imply that anyone is so please don’t take it that way.
Definitely, please feel free to not do anything as that’s your prerogative. I can identify with the sentiment, “I don’t work for free” but posting a link or two isn’t really “work” is it? As far as being a free info center, that’s why I suggest (if you can) to pawn them off on a site (such as a the WP Codex) that is an info center. Remind people that there’s loads upon loads of info out there but if they can’t bothered to read / search / do for themselves then (if you’re available), again suggest your services. I agree you can’t satisfy everyone all the time but you can often satisfy many much of the time. Leaving someone hanging that could be helped rather easily often can turn out to be beneficial in the long term. You can loose sight of that if you’re solely focused on the short-term.
I often ask questions about if product x supports feature y. If the answer is no, then I ask how easy it is to implement by author / myself. However, I never expect “enhancement” requests (not bug fixes) to be fulfilled without purchase. I’ve certainly had cases where the author has surprised me by doing so. In most cases like that, I’ve bought the item. Not everyone will though. It’s a gamble. I’ve also sometimes just bookmarked an item for later or completely passed on it if it didn’t do what I want at that time. If you say, “No, it will never happen.” then I won’t bookmark it, if you say “Maybe (or similar)” then I may bookmark it for later.
If you’re making all sorts of enhancements before purchase for a particular prospect, then I’d say you might be enabling the situation by not properly “training” your prospects / customers. You’re in control. You can decide to what implement or not implement (and when). You can update anything in the demo and tell them they can benefit from it when they’ve purchased. Doing anything else may be inviting the abuse you’re talking about. Making loads small changes or a few complicated one for an non-customer would also seem ill-advised. That’s certainly your option though.
Any product behaviors / malfunctions that you agree are “defects / bugs” though should be dealt with swiftly as these very different from “enhancements” to me. If I later return to a product that I previously spent the time to inform the author about one or more issues and they’re still there then I often remove that from my bookmarks within 7 days. Where do I look to see if you’ve corrected the issue(s)? Your live demo and / or change log (whether posted on the product details page or elsewhere). If your live demo isn’t updated yet but you did update it, I won’t know if I can’t see your change log somewhere public before purchase.
