There are many things to be considered to know if a company pays you referral commissions and you are not cheated.
1. The site is genuine
2. You DON'T Cheat with false sign ups
3. If the referrals are active
4. If the company is at a profit.
5. If the company has a reputation
6. Reviews from sites and forums like Trust Review, Beer Money Forum and social media especially Facebook Page.
This checklist will give you an idea to know if the company pays you or not.
It's difficult to objectively investigate the honesty of websites with their referral systems;
(you can't refer yourself to do a spot check, and unless you know all your referrals personally, it isn't possible to assert whether or not they are truly inactive on the site, or if you are being lied to).
However, in a few instances I had opportunity to "spot check" my referrals earnings. I discovered that even some reputable, profitable and genuine sites skim your earnings:
- I caught one website red-handed swapping out one of my active referrals for an inactive one! This website, and one other that I found, just blatantly doesn't link up all your referrals to your account (MOST referrals are not linked to your account).
- Three other websites were nullifying the earnings from entire referrals at a time (making thse referral seem inactive, despite them being active in reality), a few referrals at a time, starting from the most active referrals, starting even from the first week after acquiring the referrals, in such a way that you never have a referral active for more than 3 months.
- One website stopped paying referral rewards for almost a month (system upgrade apparently) but never credited my account for back payment of referral rewards.
Regarding reviews, I have not seen many (or any) reviews that provides objective information concerning referral rewards.
Going by the reputation of the website basically means you must trust the website.
Referral earners need a union of some kind, that can somehow do independent bookkeeping of referrals and earnings to keep websites on their toes.