Trocamania is a reward scheme, it gives you trocas for doing certain things.
You earn Trocas by surfing web sites
Answering special troca questions
Doing surveys
Referring friends
Spending at certain web sites
Placing a banner on your web site
The amount of trocas earned varies bit, every day you get 5 trocas for answering a daily question. New partners offer trocas and it is one of the easiest reward schemes I have done.
The potential is not that great, and while you can earn in the UK the redemption sites are all American.
It is good if you want amazon vouchers, I just received a $10 voucher and it only took a month, saying that it only takes a few minutes to do each day. It' s not like beenz were you go hunting on the various web sites, all the trocas are earned on the troca web site, making it really simple. One of the biggest ways to earn is referring you get 75 trocas for referring each friend.
A $10 amazon.com voucher cost 833 trocas so it really depends on what you are looking for, it may be okay for some but not for others.