Internet is a great network, with a lot of business, with a lot of users, in continue growth.
It gives a lot of commercial opportunities and a lot of Socities have realized that it can be a means of publicize their products.
So, some of these Socities propose spot banners to users and pay them to surf through Internet.
Yes, You watch advertising and they pay You !
Moreover, You can also tell your friens to join (free) to these Societies and they will pay you for each hour your friends surf the web.
Thanks to some Socities, You can earn also $0,6 for each hour you are on the web and $0,2 for each hour your friends surf the web.
You also can join more Socities at the same time, increasing your cash.
Here belove there are some links to the Socities that "pay You".
It is not a complete list and it will often updated.