I am not sure if they operate a paid-to-surf system, but free members earn 20% of what their referrals spend on purchasing credits and/or upgrades. This is an autosurf site, just keep that in mind. It is a traffic exchange based on surfing, not investing.
Also, if you do decide to upgrade your account, you earn 50% of what your referrals spend. That is the incentive to upgrade, as well as earning a better percentage of your credits back when you surf (i.e. better surf ratio with upgrade.)
I can honestly say that I have cashed out twice so far & gotten paid really quickly via Paypal. They offer a low 5 Euro cash out, and for me, this is extra sweet because my currency is the US dollar, so I get a little extra each time I cash out. Not really, but it feels that way because of the currency exchange rate between the euro and the dollar.
I could have cashed out a 3rd time, but the next time I had enough in my account, I took advantage of a special they were running of 10,000 minutes for E 3.95. I am now sitting with E 3.30 in my account & waiting for the day another of my referrals buys minutes or an upgrade so I can cash out again. I have roughly 180 referrals so far, and I continue to get a few new referrals every week.
It seems like TS is into the tens of thousands as far as member count goes. My referrals surf enough that I really don't have to, and TS generates about 1500-2000 hits per day to my sites. If I surfed more, the traffic I get could potentially double. Traffic is delivered quickly and has a very high unique visitor ratio. Lots of people surf this site every day and they pay attention to the rotation because they also offer great bonus minutes via surfbar bonus links.
Any other questions, just let me know. This is a great autosurf traffic exchange and it seems to be very reliable. I've been a member for about a year and I've been loving it.