Please let me know the answer for this…
Thanks in advance,
Rose
Pay per click is where you get paid when people click on the link.
It pays more than Pay per View because only a small fraction of those who view the link go on to click it.
It pays less than commission because not everyone who clicks the link goes on to buy.
[B]I assume you mean PPC in terms of getting traffic given that you posted it to the SEO forum however if you mean PPC in terms of driving revenue, well then you need to take, and reverse this entire post… or just read what felgall said… it’s a lot shorter and just as relevant 
[/B]Pay Per Click advertising is bidding on the paid portions of search listings [or other sites].
The benefits are many but in short, unlike with SEO, you can insure a placement and message scaling up or down as you see fit.
For ecommerce sites this is extremely valuable as the traffic tends to come at a low enough cost and with enough focus to convert, profit from either in the short term or over a fairly quick life-cycle, and keep building. When you are selling you can’t afford to have dramatic & unforeseen dips due to changes in algorithms or linking partners so paying for traffic becomes much more reasonable. Thus while seasonal and market effects come into play, PPC allows you to maximize the up-swings and aggressively market into the lulls to turn as much profit as possible, or sometimes just keep the business running in full swing depending on how major your cycles are.
The same is true in lead generation and other direct profit based businesses when traffic is measured on strict conversions and brings back revenue to reinvest, further growing campaigns.
For content sites things can be harder. Ideally traffic is modeled against revenue and formulas can be applied to see how PPC performs with some sites playing a direct arbitrage game [each click is measured in vs the revenue it makes to see how much you can spend and still profit using a rolling average]. However because the revenue per visit tends to be lower for content sites, it’s important to have clear goals… whether it’s to get users who are likely to engage over time, jump start traffic, pass off to another program or the likes.
Probably not exactly what you were looking for but while the concept of paid traffic is straight forward, the reasons why people would buy it is often missed by those use to purely organic tactics so I figured I’d provide a little more justification.
You’ll see a lot of people chime in and suggest PPC is either a bad route or just short term but the truth is, if you have a solid revenue model from commerce, lead gen, memberships or even ads, PPC can be a very good long term way to grow and insure a constant traffic flow.
In the short term and on a limited budget, there’s an entirely different benefit… testing. With the lean approach you spend $50 on search and see how people respond to your site… 100% bounce rate on a relevant term and you know something is off. It’s much quicker than waiting for people to come in and better than waiting for a large launch to know you hit, or missed.
Don’t forget that most engines have moved to a quality score that hyrbids bid, clicks and page content to place relevancy above sheer spend. Thus if you don’t perform well you have to keep paying more and more to hold the same spot.
Ok some answers are too long and some are too short and some dont even make a lot of sense.
Pay per click in short is money gained when someone click on an ad you placed on your site.
Benefit is that you can earn some extra revenue =)