> so many get rich trading forex ads all over the web Anecdotally, as a publisher, the CPCs (cost-per-click) are quite high, likely to make up for low clickthrough rates.

In other words, it doesn't seem like many people are interested in it, but the forex shops must be making fairly good money when they get a new customer.

tl;dr it's high-margin and low volume in terms of actual customer counts.