Hm, there are a lot of interesting links in the related questions to my own question. I'll still ask it though:
I love stackoverflow for the high-quality feedback I get. I use it essentially for my job in every-day work, as well as for important design decisions for my Java open source library jOOQ. While my questions are of technical nature and interesting to the broad public, I admit that I don't dislike the fact that I can subtly advertise jOOQ a little, when putting my question in the proper context. Now here's my meta-question:
How much advertising is OK in my questions, given the fact that I do not have any financial interests, but that I think I can give something to the community, while working on an interesting, fun, "instructional" project?