AdSense marketers had long back understood that good research on keywords multiply their efforts in order to bring in most income. The only problem is, it will take a considerable amount of time to conduct all the research necessary to find the best niches and keywords.

"Spam is like the aliens among us. They look like us, dress like us – but they also eat the houseplants." -- John Holbo

Today you see Google Adsense ads on almost every other website on the Internet. These websites do this to generate revenue from these Google Adsense ads to support themselves and hopefully make some profit. The problem arises when a website's owner creates fraudulent clicks for the sole purpose of generating Google Adsense revenue. That is to say they manually click on the links themselves, or through multiple different computers, to simulate different people interested in the advertiser's website.