Select a representative sample: Selecting a representative sample from your sampling frame is also important for collecting valid and reliable data about the population of interest. For example, if you are sampling from a large database of customer email addresses and only wanted one response per household, you might want to cross-check each email address against mailing addresses and remove duplicates to avoid some households having a greater probability of selection. Then you would likely draw a random sample from the remaining list of email addresses.
Pros: CashKarma operates within an app, which makes for a simple, self-contained user experience. You can also watch videos, complete sign-up offers and earn bonus achievement badges. Plus, you’ll still earn points even if you don’t qualify for a survey — based on the amount of time you spend in a survey you’re screened out of — and you’ll earn an easy five points a day when you check in.

I did a lot of research over the weekend to find out what survey panels still pay in cash because, as you may know, many of them are now beginning to offer just gift cards to Amazon or other retailers in exchange for your time spent. I came up with a list of 20 ways you can take online surveys for money (although depending on the company they might also occasionally offer other rewards like Amazon gift cards as well).

Its free to use, no subscription required, you can create as many surveys and collect as many responses as you want, There are no restrictions on making surveys. If you want to view all responses it's free, no upgrades to paid plans are required. However, if you are just starting out or need only a small poll or survey, eSurv is exactly what you’re looking for to make your first survey.
It’s easy to earn cash for surveys. How much you get paid completely depends on how many paid surveys you attempt and complete. Each online survey has a different payout, with some offering as much as $50. Most will pay less, but also take less time. Expect to earn about 40 to 200 SB points per survey (100 SB = $1), with occasional opportunities with much higher earning potential.