Pay per click (PPC) also known as cost per click (CPC) advertising has become one of the biggest forms of advertising in the history of the world. Due to overwhelming competition and ever changing rules, more money is typically spent on these campaigns than organic campaigns.
One big advantage to CPC solutions is faster results. You control placement and to a certain extent the level of traffic you will gain. Where organic campaigns can take months to develop substantial new visitors to a website, a CPC campaign will increase your online traffic within a few hours after launching the campaign. Gaining more targeted, high quality traffic is more easily obtained with these campaigns because you have more "immediate" control.
A major disadvantage; when you cease your CPC campaign, that traffic simply goes away.