[zilian]

A quick google search gives me several tools for this : Formstack, Omnisend, Zuko Form Analytics...

[edmundsauto]

AFAICT Formstack and Omnisend are marketing automation and analytics services, not automatic split testing. I got out of the marketing space a while back but I do appreciate the cross check! However it doesn't look like those products are doing exactly this.

[nehagetschoice]

+1 that's my understanding as well.