Hello @hanfoosh. Pollfish uses Advertising ID in its new SDK v3 that is live since last month. You can check it by yourself by disabling Interest-based advertising in your Google Settings. When disabled no surveys are delivered on your device
You can incentivize your users to complete surveys, however you should not force them to do it (This is against the policies). So you can give this as an option to them.
If you have more questions or concerns I will be happy to help.
It is true that survey campaigns start and stop at a short time since market research companies want a limited number of completed surveys for each campaign (usually from 1k to 2k), so the model is quite different than classic advertising campaigns. This is why we are working around the clock to bring more and more surveys and keep our developers happy!
Have in mind that when no paid survey is available through your app nothing is shown as if you had never integrated Pollfish before giving you just the option to boost your current revenue with other ad networks that you already use when survey inventory is available!