Once you signed up, you'll receive a free 1,25 $ balance. You may use this to test the servers. Once your trial is over, all servers are beeing deleted.

That's correct you get an automatic credit for $1.25 which is the equivalent of using a 512MB virtual server for free for almost an entire week before you incur any charges to your account.

If you aren't satisfied just destroy the virtual server before that time is up and your account will have no charges against it.