Good interview with Garrett Dimon who founded and has bootstrapped Sifter for several years now.
An interesting part was his experience with eliminating their cheapest plan:
Our conversion rate from site visitor to trial plummeted. It decreased by 50%. So we had 50% fewer trials signing up. However, our total amount of $29 plans skyrocketed. Fewer people signed up but the ones who did were much more likely to sign up, and they were fine going ahead and signing up on the $29 plan. We were definitely were happy with how it worked out… lots of the customers who would have signed up for $14 went ahead and signed up for the $29 plan without skipping a beat.