Originally Posted by sambucas

I promote Sextronix, but I'm 100% mobile so not sure how relevant it is for your case. Anyway some of their sites have a signup page that offers to enter username and password but is asks for payment only on second page. So users enter their usernames and passwords and click on 'Sign up' button just to see how much does it cost and that's counted as an attempt. So some days you may have fairly big amount of attempts. BTW Sextronix mobile converts pretty well.