Without a free tier, I'm out. I want to make the purchase decision on my timeline, not yours. I've operated several freemium services so I know how cheap, easy and important it is.
1) With the demo on the homepage, you immediately get a good idea of the usefulness of the tool.
2) I'm not really interested in a freemium model where I support a large base of non-paying users.
3) I'm trying to see if this is worth working on, and the number of people who are willing to pay is a good indicator of that.
I'm interested in your thoughts on the benefits/downsides of this approach.