Should I join Ciao? How it works?

Tweet

I read everyday about ciao and that it is not a scam one, and I am thinking of join. At first i thought it was a survey site, but there are people here that say they pay you to write reviews. I am a bit confused. I visited the site but I couldn't understand how it works. Can you help me on this? Also I will need a referral link, so I can join under you Thank you in advance