It also depends on how you want to promote a product from CB (or any other service/product).
As Zak_A is saying, when a product has a high gravity (200+) means there are a lot of people who are promoting this product, so a lot of competition you need to beat.
On the other hand if you are trying to promote trough Solo Ads or similair services, you don't have to care about this as you will be advertising directly to very high quality traffic already interested in the niche.