The number one and already famous U.S. based site that falls directly under this category is 

What do you do in this site to earn money?Money is made at the end of every month.The concept of the website is to involve people activities that are funding itself to the site and finally share the net profit among people i.e. members.People activities include logging in and out twice a day i.e in the morning and in the night before hitting pillow,playing fun games inside members area,checking mails,chatting and earning people dollars which you must buy either  by paypal,credit card,prepaid card,debit card ,western union or even by mail cash and also earning cashback through "Earn fast cash button" in the right mid corner.Furthermore referring friends and for U.S and Canadian members taking mail cash offer i.e. allowing mail postcards to arrive in your mailbox will boost again your peoplepoints.This feature will be added in other countries as soon as the number of members in the specific country gets sufficient enough to get advertiser's attention.

2. The another promising site under this category is 

Now, at geostring no any relatively hard work is involved than peoplestring.When you go there and signup you are entitled to get immediate $10 signup bonus.The catch behind this is you are signing up as their audience.Each week you get mail from geostring that says you to confirm the delivery of the mail by clicking the link inside the email.You do it and visit 4 advertisers link that asks you for about 1-3 minutes and you're done till next week.The more splashing feature of geostring is you get even more credit and money by telling others and referring others to join with you.

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