In the past, "we've talked about ad placements that are prone to generate invalid clicks -- for e.g., Mike noted that publishers should be careful about placing ads too close to navigational controls or other clickable page elements," noted Dan Zilic. It's in the best interest of user, advertiser, and publisher to avoid implementations that lead to invalid click activity.
"As you can imagine, users aren't very happy if they accidentally click an ad instead of a link and are directed away from your site. Advertisers also don't want to be charged for an invalid click (don't charged). And why should publishers care? Well, if we see that most of the clicks coming from your pages are invalid, we may need to disable your account to protect our advertisers," explained Dan.
"On Flash-based game sites in particular, you'll notice that ads are often placed very close to Flash player where the game is played[…]We've seen many cases where ads were placed too closely to where the action was taking place, generating many accidental clicks. Since each game and site are unique, we can't advise publishers on an exact distance between ads and games, but we do recommend a minimum distance of 150 pixels between the Flash player and ads.
So, in short: Moving the ads further away from Flash games decreases the likelihood of accidental clicks and increases the number of clicks leading to business results for advertisers," advises Google.