Personally, I don’t think RLSA are that interesting. Its a way to pay less per click for revisitors, but in the end, you pay again for the same user 💸. It means that the visitor isn’t ready to buy. As simple as that. You don’t want to pay (too much) for people who aren’t ready to buy, right?
So… The biggest gain is upfront, at the first click. Making it as relevant as possible. Meaning.. you need to understand your audience, right? People, not sessions. Right?