We already know that click-through rates on online display ads are abysmal. Now a study from the startup Pretarget and ComScore revealed that even when a user clicks on an ad, the correlation between that click and a conversion is virtually nonexistent.

Over nine months, Pretarget analyzed more than 260 million ad impressions across the campaigns of 18 advertisers, the company said, and tracked conversions ranging from filling out an online form to downloading software. In the analysis, Pretarget found that the Pearson correlation (a common correlation methodology) between clicks and a conversion was 0.01, the lowest correlation rate among metrics tracked in the study (a 0 result would mean there is absolutely no correlation, while 1.0 would signify the strongest possible correlation.)

The findings lend credence to those who have long said it's time that the industry makes a serious move away from measuring campaign success based on click-throughs, the foundation of online display advertising that's looking more flawed by the day.