So I decided to try it out. They offer 25000 page-views per month and two fonts per site. I don't like either of these restrictions, especially the second one. So, I looked for alternatives and I found Google Web Fonts.
Using Google web fonts is very easy. You just need to select a font and then click on the Use this font tab and you have the instructions about how you can use it in your web page.
Font-face backed out because Google entered this market. However, you still have other alternatives like WebINK.