THE ADS THAT FOLLOW YOU.
Yes, it can be annoying but it’s also effective.
If it wasn’t, they wouldn’t be doing it would they? Retargeting works when someone visits your site but leaves before completing a desired action – like buying something for example. So when they’re online again, they see your retargeted ad and it reminds them to visit your site and complete what they started. When a typical conversion rate is 2%, perhaps you might need help to close some of the remaining 98%.