There is no point in pretending that we are all here to learn something and to share that knowledge with others, because there are certainly those for whom the forum is the only place where they come to make money. Most do so by participating in bounty campaigns, some in signature campaigns - but such members are very easy to identify.
The purpose of the forum should be for people to discuss, exchange ideas and be a little smarter at the end of each day than the day before. If, in addition, some get the opportunity to earn something by promoting someone or something legitimate, it should not be seen as a problem - of course until such members become what we call signature spammers. Anyone can report such bad posts, but the biggest responsibility is still on those who run such campaigns and need to separate the good from the bad.