Not the original commenter but I rarely sign up for things just to try out a product unless I'm already sure it's going to solve my problem.

I don't know how they're going to use my email. Are they going to send me useless emails in the future even if I decide that I'm not interested in the product? Are they going to make me confirm my email instead of letting me right in to try it? If I don't like the product can I delete my account or do I just have to forget about it?

I like when I can try out a product with as little friction as possible. To be completely honest when this happens it can sway my decision to use the product.