Thank my son for this tip because I’d never heard of it. There’s a little Android app you can get called Google Opinion Rewards. They occasionally ask you a couple of survey questions and in exchange for your answer(s) they credit your Google Play account with 20 cents, 70 cents, or some other small amount. It adds up pretty fast and lets you get some of the nicer paid apps (with no ads) that you might not have been wanting to spend money on. I bought the local Storm Shield weather app that’s from Scripps. A $4.99(?) app I’d wanted but was too cheap to pay for. And bought an upgraded version of Trivia Crack so I don’t have ads in that. I had an $18 credit built up and then got a $10 gift card for Christmas, so I’m now looking for the best way to spend the money. Nice dilemma to have. And a good solution for all those miscellaneous little apps that nickel and dime you to death.
I’ve been doing these surveys for a couple years now. I was up to over $20 at one time. It’s handy to have as I prefer to purchase app upgrades for no ads when they’re available. Or if I’m buying something stupid for a game, which isn’t that often but occasionally I do. It seems to go in waves. I’ll get sent a bunch of surveys for several weeks, then I won’t receive anything for a while. They’re quick and easy to do. Often redundant.
When I first started, I racked up about $15 in a very short time. They kept sending me the same two or three questions, over and over. But I was getting credit, so didn’t care. But they’ve gone silent the last couple of weeks. As you said, it seems to come in waves.