If you're promoting anything related to ‘make money online‘ and/or ‘internet marketing‘, ad exchanges are a great place to start because they are free or provide paid advertising which is relatively very cheap compared to the advertising you can buy from larger media companies such as social media sites and search engines offering pay per click advertising.
Ad exchanges are basically sites where people who want to promote their products and opportunities can post ads to each other, either via email or on site advertising such as website hits, banner ads and text ads.
Whilst they aren't much use if you're trying to sell lawnmowers, they are pretty effective if you want to promote online advertising products or anything related to earning money from home, as nearly all the people using ad exchanges are trying to make money from home, with varying degrees of success.
One thing you need to be successful with ad exchange marketing is tracking as some sites yield absolutely no results at all and some are brilliant. I track my results with Clickopia to check which of the ad exchanges I use are currently working the best.
Here is a list of the ad exchanges I am getting the best conversions with at the moment. This list is periodically updated to reflect which sites are currently delivering the best results for me.
If you use ad exchanges and you're getting good results with them, please feel free to comment with your affiliate links for the sites which are delivering the best results for you. As long as your comments are relevant and not negative toward any particular ad site or person, I will approve them. I am always on the lookout for new traffic sources.