How to login user automatically after registration

I'll have another look at it when I get a chance. Working on other aspects of the site now.

But in terms of bots, when a user creates an account on my site, he cannot do anything without paying. My accounts are not needing email verification. But the user still needs to pay before being able to do ANYTHING on the site. So how can bots cause me any problems? Haven't had any problems with account sign ups from bots as of yet, and automatically logging in a user would not allow him to do anything bad that I can think of.