In this video about how to find a profitable niche for email list building the narrator offers some tips for finding the most popular products to sell on Clickbank. Similar methods can be used for affiliate markets like JVZoo, Warrior Forum Special Offers, OfferVault and many others.
The essential focus is on finding products that fill a specific need or can solve a problem. Relationships, Money, Health and Beauty are some of categories where profitable niches can be found and affiliate opportunities are available.
If you missed the first video in this series, it can be found at Email List Building: An Introduction.