They are deceptive. Sometimes they don't recognize your transactions so you lose your cashback. Uninstalled.

The cashback is incorrect. I get a lower cashback than the published rate. It's cheating.

It does work, but the notifications are incredibly annoying and can't be disabled

Top Shop!!!

Beware that half the time the shopback button disconnects itself when you go to the payment page and therefore it does not recognise that your purchase should be attributed to shopback. I have had to fill in 5 missing cashback forms in the last 3 weeks, and need to do 2 more when the waiting period is over.
You shouldn't have to check the connection every time you click a button on the website you are trying to purchase from.

free moni

The rewards are not worth having this obnoxious add-on with it's constant annoying pop-ups. Use Cashrewards instead - the notifications are much subtler.