Would be interesting to see the effect of free trial length on their conversions (specifically shortening to 30 or 14 days and measuring the effects). At a company I work for, we found that shorter free trials actually led to more conversions.
One of Heap's most important value props is retroactive analysis. You forgot to define an event upfront? No problem - it's available for you to analyze across your app's entire history.
A 60-day free trial helps our users make better use of retroactive analysis than, say, a 30-day free trial. The longer you accumulate data via Heap, the more viscerally you understand this need.