This restriction is there just for the last 2 hours. You could do 5 analysis without any account before. The reason is that I got a huge traffic from HackerNews and the service was not prepared for such a big load and were (are) there many technical issues. I know, it is my bad but I really did not expect that people will love this service (concept) so much that it will go on #1 page on Hackernews.