Google

www.google.com/adsense
As with most things online, Google have cornered the market in giving money away as well. Their Adsense programme is the proverbial daddy of passive revenue streams as it allows the webmaster to automatically display adverts on their website relevant to their content. There is no need to select products or destination links for your site, Google does it all for you. If your website is about reviewing Golf courses in the UK (hmm, I’ll write that one down) then Google will automatically display adverts for Golf clubs, golfing holidays and golf equipment.
Assuming you optimise your website correctly with advert location and colour schemes you can potentially achieve a CPM of over $4. This means $4 for every 1,000 impressions. So if you have 1,000,000 page impressions in a month you could make over $4,000 just from Google.
That’s worth signing up to Adsense for. Google Adsense makes direct deposits into your account each month once you’ve earned over $100.