Adding CAPTCHA to Marketo Forms

Carrie, I don't have a good CAPTCHA solution for you, but I'd urge you to reconsider adding one to your forms. They present another hurdle to someone filling out a form, resulting in fewer form fills, and that cost might outweigh the benefit of having spam fillouts removed. 

Carrie,

I did a quick search and found some solutions
https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#safe=active&q=marketo%20forms%20and%20captcha

http://stackoverflow.com/questions/14219367/marketo-spam-filter-without-captcha

I don't know of a specific integration, but if you have a Captcha provider, I'm sure you can work with a javascript developer to add this to a Marketo form pretty easily. I would do this as Custom HTML in the LP or on your main website with the embed code or API.

I wouldn't add a Captcha - since there are so many ways that Marketo lets you filter spam leads out w/o having to increase the "difficulty" of your forms for your regular users.

I use a combination of exclusion lists (email domains, phone numbers like 12345, names like John Smith) and inferred country filters that exclude people that aren't in English speaking countries inside my territory.