I think this might be more suited for the Coffee Break folder.
I use eBates and Raise, often in combination with each other. I also took the time to learn the ins and outs of the cash back options available on my credit cards and take advantage whenever possible. Nerd Wallet is a great resource for learning about that. I also got a nice bonus for opening a new checking account last year, if you're in the market for that it pays to do the research as to which bank is offering the best incentives.
In my experience the trade off is privacy, complexity and time (shopping can become quite a headache if you let it) and the occasional "gotcha" when things don't work out as you anticipated due to misunderstood terms or some other fine print.
Regarding the bolded: That particular money earning hint has brought in quite a bit of cash for me.
It started with opening an account for Oogydh to use for his work vehicle. It was easier to keep track of his gas purchases for reimbursement if that was the only thing on that card. The new card offered points. It made me look at the only other credit card we used and had been using for 2 decades.....it didn't offer points, so we opened an account that does. Every couple of years, I have the cash value of the points applied to the balance.
Since we have excellent credit, we frequently receive offers for bonus points with a minimum purchase and interest free for a year or more. Using these offers to buy planned major purchases, I have "made" (I have the cash value applied to the balance) about $1100. 50,000 bonus points (translates to $500) if I spent $3000 within the first 3 months.....we did that one when we bought all new appliances for our new house.
One must have discipline when doing this, though. I think the credit card companies put out these promotions on the hope that someone is careless. I use the card for it's pre-planned purpose, apply the points and pay the rest off within the interest free period and never use it again.