Start out free and get people "hooked". Then start offering upgrades and limiting the free plan after awhile. So, at first. Totally free. Watch your users. How

Start out free and get people "hooked". Then start offering upgrades and limiting the free plan after awhile. So, at first. Totally free. Watch your users. How many sources they connect, how many times they search, etc. Then after a few months, set it up to be 'free for X sources' or something. Everyone else must pay. I would use it, but not often. It's pretty rare that I can't find 'something' I'm looking for and could use a global search tool (if that isn't what this is, then that also might be part of the problem -- marketing).