The site is well designed and is very fair about letting you use it as a free user but limitating several aspects. That's what can be said about the site. For further success in communication, it depends on your luck, your commitment and the other's commitment (but all this is out of the site's reach).
The main reason I signed up on this site a few years ago was to start writing letters again. I've met quite a few people and it's been such a joy to be able to get to know them through letters as well as through messaging on the site :)