I have an account on stumble upon but I have only idea about stumble upon. I want to know that how can I used it in effective way so that I can generate traffic for my site from stumble upon.
There is only one purpose of that socialbookmarking website - to help others gain a traffic.
Well you are half right. There is one purpose for "Social Bookmarking," but it is not to "help others gain traffic." It is for bookmarking websites that you find interesting so that you can then access this catalog at anytime from any internet connection. Yea.. you can submit your web pages and pray that the content is good enough to go viral, but a vast majority of the traffic generated from these sites is irrelevant or unqualified - meaning that they will not buy your products or click on your adsense. It's a bad idea and ultimately a big waste of time to try to game "social bookmarking" sites. Juice ain't worth the squeeze.
In my own experiences, you would get direct traffic from search engines like Google via putting your links and reviews on stumble upon if only you could use your targeted keywords correctly, especially for those long tail keywords.
If you get reviews for the links you added in your profile, you will get tons of traffic. I remember I got around 3000 visitors in 4 days for a single review.
But, the traffic is not too good...no one ever clicks your ads
I work with a fiction magazine that gets a significant number of hits via StumbleUpon. One thing that you can do besides submitting your pages is to provide a way for your readers to submit it to StumbleUpon (and other sites such as delicious, reddit and digg) as well.
Also make sure that you include the appropriate tags as well as an interesting summary, with the most engaging part in the first sentence, in order to encourage people to click.