Different anecdata here. Trial periods suck.

My experience is that I rarely have enough time to determine if I really like the service or if it's still just a shiny new tool to play with. I need more than 14-30 days to actually put in the work to understand a reasonably complex tool (say a CRM system) well enough to make a commercial recommendation.

Obviously this issue doesn't apply to all SaaS companies but it's probably common enough to be worthy of consideration.