For almost every niche, there are forums around online where people would flock to discuss the issues that surround it. Naturally, this represents a base of potential traffic that you could tap into, but the question that should be asked is, “How?”
Obtaining traffic from a forum can sometimes be a long process. Most good forums tend to have been established, and you will have to establish yourself within the forum so that the others there view you as an important and trusted contributor.
If you can accomplish this, then your suggestions are bound to be taken more seriously, as will your links. Before you get to this level though, you can always start off by including a link in your signature, as is the generally accepted practice with most forums. Be sure to read and abide by the forum’s rules though, the last thing you want to happen is that you end up getting banned for some offence that you did not realize was an offence.
Who knows, once you are very reputable, you could end up tapping into a huge stream of traffic from a forum.