I read one article which stats that hosting a new website and build traffic will takes some time to stand. But buying a website with good traffic will give us a good result.There are so many websites with good traffic are ready to sale.
What are you thinking about this. Is this is really profitable one?
Check the page rank and check if the website is really active and has lots of visitors before buying. If it really indeed is, you can buy the domain/site, and then you can put some ads on the website; you will be making money off the advertisements.
Buying an established website/domain with traffic is always a good idea, although a nice domain with traffic isn't too cheap. Check out namepros.com (their sales boards, especially the 'Domain with traffic' one) for a rough idea of prices
Also remember that if it does have page rank, unless you get a website on there quite quickly it can still lose that page rank (since Google would tell it's been sold, and then see the new site has no content etc). But yes, in principle it's a good idea
If you can find a site with good organic traffic (not the kind that depends on the current owner's network of sites/friends) at a good price (which possibly means inefficiently monetized) you may turn a good profit if you can do a better job at it than its current owner.
It's unclear to me, are you interested in keeping these domains, or just flipping them?