Usually, you wait until a visitor comes to your site, and cookie them while there so that when they later visit Facebook (or some other websites) they will again see an ad for your product. Retargeting works, but it could work better if you were able to differentiate between a visitor who was on your site for a few seconds and one that was there for several minutes. Suppose you could only show your ads to people who showed an interest in your product by staying several minutes to read about it. If you only show retargeting ads to people who have demonstrated an interest in your product, your ad... [...]