I wonder if part of the reason is that on shorter trial periods, people are still in the 'honeymoon phase'. When you make a good first impression, people will g

I wonder if part of the reason is that on shorter trial periods, people are still in the 'honeymoon phase'. When you make a good first impression, people will go 'oh this is the best thing ever'. Nothing ever is, of course, and it takes a while (weeks to months, depending on the product) to find out that some aspects aren't that great. But when you've made the first payment, you've committed yourself, and now you're prone to confirmation bias. After 2 months, people are more likely to have hit the not-so-great parts and may think 'meh, I'm going to try other options first'. The shorter the trail period, the more people (at least of those who actively try at all) will still be in the honeymoon phase and more likely to sign up. Just thinking out loud, I have no numbers to back this up, and I wonder how one could measure this. I guess you'd need to correlate user activity to the duration of the trial and the likelihood that somebody signs up - maybe there is an overarching trend to be found there somewhere. It would require a fairly homogeneous set of users though, or otherwise a large number of users and additional data (either user traits or usage pattern commonalities) to slice the users into more homogenous groups.