Clickbank is viciously competitive. Lots of affiliates fighting for a slice of the pie. A lot of new marketers pick the top products in the marketplace and dive in only to find they're sharing that niche with hundreds of other hardworking affiliates. Doesn't mean that an affiliate can't carve out a decent revenue stream from a crowded space, but oftentimes it's tough going.

Consider this formula for finding less-competitive CB products.

Gravity: 10-40.
Percent of sale: 40% or more.
Minimum Commission: $20

Gravity is the important number in this formula. Over 10 means a product is selling reasonably well, but hasn't caught on yet. Over 40 you start to see hyper-competitivness. 20-30 is the perfect gravity range.

Upsells: See if you can find products that have upsells. I'm a huge fan of vendors that provide this... It's a great suprise to see a sale and then a greater charge to see you've made a second commission with an upsell product. Upsell products can bolster your earnings substantially.

In no way is the definitive way to pick Clickbank products. It's just another approach to finding and promoting products. I've promoted top 10 products and done well. I've also picked products with 0 gravity and done well on those.