I've joined in but seems that it's a bit of a hassle to wait 2-3 seconds of advertisement before each result.
It's like 1 PRE = 0.075 USD = 4 searches,
up to 8 PRE per day = 0.6$ per day... maybe it's worth it when you have the time and patience, and then disable the extension.
RE: Presearch (Listed on Coinmarketcap) - Search Engine - Suchmaschine - Earn PRE Crypto Tokens for searching the web using Google & Co.