Ask HN: Does retargeting hit the wrong consumers?

[svjunkie]

I'm doing some research on a company that spends a large amount of money on banner advertising. Some of their data suggest a relationship between sales and ads displayed in the days or weeks AFTER those sales were made. That made me wonder - is it likely that banner display networks, especially ones that use retargeting, are serving impressions to users after they've already made a purchasing decision, especially in the case of high-dollar purchases? I don't have enough data to effectively answer that question, but based on the relationships I'm seeing as well as some anecdotal experience, I think there's a strong possibility that this is the case. Have any of you seen data that supports or opposes a similar conclusion?

[patio11]

A certain percentage of retargetting does hit customers who have already bought the software, either because they don't exclude previous customers or because the initial lead, the decisionmaker, and the person with the credit card might be three different people.

This is largely considered to be an acceptable inefficiency in light of retargetting's (generally pretty impressive) results.

A related minor inefficiency: I'm doomed to a lifetime of being trailed across the Internet by the ghosts of consulting clients past, because logic (which I, erm, may have implemented) suggests that my behavior means I'm teetering right on the cusp of buying their stuff. I mean, look how many times I went to their website, signed up for the trial, and did virtually everything I could possibly do short of plunking down $X,000 for the product!