how do internet sites make money such as facebook and craigslist if there free?

[Bubba]

is it from other people paying for advertisement? hoe would I go about making a website?

[Jordan]

Craigslist charges for some ads in bigger cities.
Facebook makes all it's money from ads, companies pay fb to put their banner on the site. Works similar to television works. Companies have commercials, so users can watch basic tv for free.

[Hank]

Mostly with ads. But Facebook also makes money from games.

[scoutma53]

The advertisers on the pages pay the website.
If you were to set up your own site, you would have to make it interesting enough that lots of people would visit, because advertisers would not want to spend money on a site no-one visited.

[Dinesh]

How to earn money easily through internet

1. visit http://www.instaforex.com. click on Download trading terminal.
2. Download trading terminal MetaTrader 4 from the next page and install it
3. Instaforex is the forex broker to do forex trading.
4. After installing instatrader , click on Tools --> new order , you will see Buy /Sell option.
5. Decide whether to buy the currency or sell the currency.
6. to earn more money use forexrobots .
7. Forexrobots are available in http://www.forexrobot.co.in
8. select which forexrobot to buy and place the forexrobot / expert advisor in the expert advisor folder.
9. Now you can see the expert advisor in the Navigator panel
10. Drag the expert advisor from navigator panel to the EURUSD chart or whatever chart you select for forex trading .
11. Click in exper advisor button in the toolbar for automatic forex trading

Enjoy ForexTrading.
Earn more money
All the best

[Zane]

They post links to other companies. When a user follows that link (i.e. advertisement), Facebook/Craigslist gets paid a few cents. Beleive it or not, people will and do use those links.

I noticed in an above reply, someone said you have to make your site intersting or you won't get paid. That is not true. For the advertiser, it costs them nothing, so you will be able to use them. What is important is driving traffic to your website so that people will use your adds. In that respect, try some SEO tacttics. You can learn about them at http://www.azimuthsix.com