Good AdSense niche topics are like goldmines. They are often poorly covered areas of interest that has little to no competition from other publishers. They often have good levels of demand (interested visitors) and a good number of high paying related ads. Basically a good AdSense niche is one that has:
High Cost Per Click
High Traffic
Low Competition
AdSense:
AdSense is run by Google and is basically an application for the purpose of managing advertisements. Those who own websites are given the opportunity to use AdSense for the purpose of managing images, texts as well as video advertisements on their web pages. These adverts are managed by Google and help them earn money on the basis of per-impression or per-click transactions.
AdSense Background:
Those who are looking to advertise with the help of AdSense are required to enroll with AdWords. AdSense has become increasingly popular over the years because these advertisements are different from banners with respect to interference and annoyance. Moreover, the information offered by the advertisement is related to the content of the website.