It is a scam site. I didn't take surveys, all of my points were from referring other users, but they refused to pay me due to "suspicious survey answers". They sent me the same irrelevant email template for my complaining emails. Finally, when I was able to talk with a real person they provided other fake explanations why they are not paying, like I used bots or I hide my location etc. All of them was false.
The payout is very high ($25). Don't waste your time by taking hundreds of surveys only to figure out that they are not paying. Univox uses external survey providers (like CINT) so you can take the same surveys on other, reliable sites.