So how can this site earn?

Ad revenue

Thnx 1 more qstn how a free website like Facebook earn cuz we wouldn't pay for using this site we just pay for data we use does isp pay the money?

Of curse it's enough.
Many people pay extra for HBO, and many TV series are only there and many movies debut there!

But is it enough? can you give me an example

By viewer count, plus for these channels you have to pay a monthly subscription added to your TV Cable bill.

Hbo hits, trace hd etc channels are 100% add. free. Can anyone tell me how they earn?