The article title gives the puppy image credit but I think the additional text had as much if not more of an impact on the conversion lift than the image.
"Start your 30 days free trial" text
vs
"*Sign up now* 30 days free rial. Pick a plan & sign up in 60 seconds. Upgrade, downgrade, cancel at any time." with a puppy image.
The second version is so much better because it tells the viewer what to expect... the 60 second signup, flexibility in changing plans, no long-term commitments. The dog image does help since he is looking at the call-to-action, which also draws the viewer's eyes there too.
It is a great post and just goes to show how testing can really help boost conversion. It's often a lot cheaper to grow your business by improving conversion rates than by increasing traffic.
"But we can still be fairly confident that the image was the main factor since this test had a much higher change in click through than what we typically see when we just test text vs text."
How can you be fairly confident? They broke the cardinal rule of the scientific method.
Well, it's worth noting that while we're interested in the general science of puppies and conversions, our end goal with this test was not to determine the exact value of the puppy picture, but just generally finding the best way to get people to click our call to action button...
Except you have 2 variables - puppy/no puppy; and copy A/copy B, and therefore 4 combinations. You only tested two combinations, so you have no way of knowing if the puppy or the alternate copy was the reason for the increase.
It is a great post and just goes to show how testing can really help boost conversion. It's often a lot cheaper to grow your business by improving conversion rates than by increasing traffic.