They include sites that seem to be their competitors because they earn referral fees when you buy memberships. A couple mentioned in scam forums even try to dupe you into buying the same list at other membership sites they own under different names. Naturally, these sites also have an incentive to exaggerate how much you'll earn from online paid surveys.
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.