Ask IH: Free vs paid trial?

I'm working towards the launch of my project: https://www.review123.org - a SaaS that lets you operate a network of reviewsites very easily.

At the momennt I'm setting up a trial month option and that leads to the question: should the trial be free or paid (a couple of bucks, and turning to normal price after the first month).

Target audience is small businesses/affiliates who want to operate reviewsites. Price point is 100-500 USD per month.

I definitely want to offer a trial month so people can experience the ease of the software and I don't have huge costs connected to a trial.

But should I offer it for free (more people using it) or for a small payment (only really interested people using it).

What are your thoughts?