first of all I suggest that you'll want to use text ads and you'll want them to look like anything but an ad ( because this the right the thing ). but you'll also want them to be a particular size . which size is that ? Use the Large Rectangle-With Google Adsense, you have the option of picking different ad formats. Most of the time people opt to use the Leaderboard (728x90) or Wide Skyscraper (160x600) style ads. Unfortunately, this is the wrong choice, because both look like blatant advertisements. Instead smart webmasters have found that using the Large Rectangle (336x280) yields the best amount of click-thrus. the second best is the 300 x 250 - the medium rectangle this ad block size is really useful when you went to have two sets of ads side by side . they fit on most web pages just perfectly ! stay away from the 468 x 60 ad block ! one of the first things people do when they sign up for adsense is to grab a 468 x 60 ad block I have a theory about why they do this . It's the same theory that explains why the 468 x 60 block does not entice clicks Most sites owners have the mindset that when they put google ads on their site , they must place the code that conforms most to traditional web advertising . and that would be.... ? Yup ,the 468 x 60 . and that's exactly why the click through rate on this size is very low even among advertisers who use images on thier banners > the 468 x 60 blocks screams , "Hey ! I am an advertisment ! whatever you do , Don't click me . In fact , you should run from me as fast as you can !" In all but a few special cases , I have found the 468 X 60 ad block to be completely ineffective , and recommend igonring it the same way your visitors do .