I signed up for the sight today.

I had to go request at least a dozen versions of the captcha on the registration page to find one that I thought I could read. It took about a half dozen entry tries till I finally entered one correctly.

I came pretty close to throwing my hands up in the air and saying forget it. How many people do you think have done exactly that? My guess is a lot.

I understand the need for something like a captcha to prevent spammers from creating logins, but this particular one may be presenting too high a barrier and actually costing you users. You might want to switch to one that--while still machine unreadable--is a little easier to read with the naked eye.

Just an observation based on my registration experience.