The answer to this is simple.  CAPTCHAs negatively affect conversion rates.  But, they have a purpose beyond simple conversions.  Their goal is of course to stop computer robots, thus preventing spam emails, answering poll questions and uninterrupted downloading of material from photo and video websites.  So, they do have a real purpose that compensates for the loss of a point or two in conversions.

Recently, an article posted to moz.com discussed CAPTCHAs in detail, including their history and some of the latest attempts to make the process easier.  Some of the newer approaches range from watching a video and answering a question to answering a simple math problem.  These “solutions” to the “blurry characters in a box” are still a problem though.

The takeaways for me of this article came from the author’s (tallen 1985) conclusions and the some of the submitted comments.  Here are his three main points:
•    If you are using CAPTCHAs just to prevent spam e-mails, is it worth the loss of conversions? 
•    Are the needs of the visually impaired potentially a factor for you? 
•    By using CAPTCHAs is the industry pushing its technology problems onto the consumer?

A few people wrote in to say that they have essentially added a field to their forms where a person is asked to solve a simple math problem.  This is less intrusive for the consumer and stops the robots.  Seems to be a decent solution to the problem.

There was another quality suggestion which was remarkably simple.  Add a checkbox.  The copy would essentially say that “to improve your user experience we are trying to fight computer robots…please  check here to confirm you are a person.’  A simple check box is all it would take.

The lesson here is the importance of optimizing the customer experience.  When was the last time you walked through your sign-up or purchase process as if you were a customer?  We suggest you do it today.  Make any improvements you can to make the user experience, and particularly the buying experience, a more pleasant one for consumers.