Value to the community is primary to StackExchange. It is incumbent on participants and moderators to add value. For the latter we must wield the knife of moderation conservatively, erring on the side of maintaining democracy and free speech. That said, I submit that even an answer with commercial/exposure aims is okay as long as it adds value. That's the simple answer.
Where we are getting crossed up a bit is by having to evaluate whether or not a "use this extension" answer is well-considered or purely promotional. This will be an inexact practice, and it will be subject to our communal knowledge of the author. For example, if Alan Storm posts a link to some extension (his or another's), we know from history and overall contributions that the goal is almost certainly informational. (Alan will also not provide a link-only answer.) When there is not much context to evaluate a post (e.g. new user), we should be informed a bit by StackExchange norms:
Stack Exchange has automatic filters in place to ban answers from accounts that have contributed many low-quality answers in the past. These filters help keep the quality of our sites high. https://magento.stackexchange.com/help/answer-bans
SE has automated the process of identifying & mitigating low-quality content. This includes sparse/link-only answers. We are well within our rights to insist that answers meet this standard and to moderate answers (and users) which violate this standard.
Read the question carefully. What, specifically, is the question asking for? Make sure your answer provides that – or a viable alternative. ... Any answer that gets the asker going in the right direction is helpful, but do try to mention any limitations, assumptions or simplifications in your answer. Brevity is acceptable, but fuller explanations are better.
Links to external resources are encouraged, but please add context around the link so your fellow users will have some idea what it is and why it’s there. Always quote the most relevant part of an important link, in case the target site is unreachable or goes permanently offline. https://magento.stackexchange.com/help/how-to-answer
The first paragraph tells me that answers need to be "in the spirit" of what the OP is asking. Therefore an answer of "it will take forever to do this, here's an extension which does what you need" can be in the right spirit provided that the answer provides further qualification.
So, we probably need to stick to SE norms as much as possible, but in order to combat promotion-only posts which are not well-informed enough to justify the suggested product, we should have some rules of conduct:
- Remind that link-only posts are verboten per SE norms
- Answers which link to extensions (commercial or paid) must provide some experiential context (and ideally a programatic peek under the hood)
- Answers which link to extensions (commercial or paid) to which the author is connected must state this connection
- When a user exhibits obvious patterns of linking to one provider's extensions, the objectiveness will be evaluated and those posts & user account become subject to moderation
I think that #3 is the most important, and that #4 should be subject to moderator consensus (more than one moderator required to act)