Ok, I sell self-hosted software with a one-time payment (no subscription). Isn't a 14 days trial enough? Would a 30-day trial do better? Or a 60 days one?
So far, people who start using the trial usually convert, so lengthening the trial will likely only decrease this. What it could improve, is the number of customers who are willing to start using the trial, thinking 60-days is a lot of free usage.
Thinking on this more: this wasn't the whole truth. I also have Keygen CE, which is the free self-hosted community edition, which could act as an unlimited-limited free trial (limited in the sense that it excludes EE features).
So far, people who start using the trial usually convert, so lengthening the trial will likely only decrease this. What it could improve, is the number of customers who are willing to start using the trial, thinking 60-days is a lot of free usage.