Google Adwords and Yahoo Search Marketing - formerly known as Overture - are the two largest ppc programs in existence. This is because they are the two best ppc programs, offering advertisers the best results. Even though both programs work basically the same, there are some major differences that must be considered.

One of the biggest differences between Google Adwords and Yahoo Search Marketing is that with Google, you never really know how much you will be charged for each click. You only know that it will not be more than what you bid for the keyword or phrase. With Yahoo Search Marketing, you only bid one cent over the next highest bidder. For example, if you bid $1.00 for a specific keyword or phrase, and the person who bid the amount directly under you only bid .50 cents for the same keyword or phrase, when someone clicks on your listing, you are only charged fifty-one cents for the click.

There is a difference in the maximum and minimum allowed bids as well. Google Adwords maximum bid amount is $100.00, which can keep search engine marketing more affordable for everyone. But Yahoo Search Marketing's maximum bid is $999.00, with a minimum bid of ten cents. Google Adwords minimum acceptable bid is five cents.

As one of the best ppc programs, in Google Adwords, the amount you bid on a keyword or phrase is not the only factor in determining how well you place on the results pages. Your CTR (click through rate) also matters. The CTR is the number of times someone actually clicks on your ad in relation to how many times the ad appears on the search results pages. This can allow your listing to appear ahead of people who bid higher than you in some instances. Of course, this works both ways, as it can also allow the listings of those who bid under you to appear before you.  Google does this to reward revelance.  Google figures if more people are clicking on your offer than the person above you, then your listing must be more relevant to what the viewer is searching for.  You can save a lot of money with Google if you are write effective copy which strongly relates to the keywords you are purchasing.

Yahoo Search Marketing doesn't do this. Yahoo only pays attention to how much you bid, but if your click through rate remains low for a long period of time, Yahoo Search Marketing will drop your keyword or phrase. Google Adwords, on the other hand, will drop your keywords or phrases if they have potentially low click through rates.