[eluser]Gromozeka[/eluser]
Err... If you prefer to count number of successful logins, then I agree that 'user_profiles' is not a best place to keep it. The good practice is to add an integer field to 'users' table (with 0 as default value) and update it by calling '$this->db->set(...)' in 'update_login_info' method of 'Users' model. Here you will count both normal logins and auto-logins too.
PS: Would it be simpler to analyze usage of your site with Google Analytics?