With Google AdSense program, any website can easily become a bill-board:
1. No experience necessary: Google AdSense program offers earning opportunity to every webmaster. The only criterion is that you should have a website (and your website should be compliant to the AdSense program policies). You dont need to know anything about advertising or advertising media etc. Just enroll with the Google AdSense program and Google will take care of designing the Ads and serving the relevant Ads on your website. So, no special designing skills or coding skills are required for getting enrolled and using Google AdSense program.
2. No need to look for advertisers: When the commercial value of websites for advertising was recognized, webmasters started looking for increasing traffic to their websites in order to make their website worthy enough to attract advertisers. Even then, getting advertisers was not easy. So, they could not really derive any monetary benefits from the traffic to their website until an advertiser actually bought advertising space on their website. However, with Google AdSense program, webmasters start earning revenue from the day they join the Google AdSense program. As the traffic to their website increases, so does their revenue.
3. No need for tracking revenue: Google AdSense program will also take the responsibility of tracking the revenue that you earn from serving the Ads on your website. You can just login to your Google AdSense account and check your earnings. Moreover, you have various reports and statistics available to you that you can use for enhancing the performance of your website on the Google AdSense program.
So, Google AdSense program has really made it easy to convert a website into revenue earning medium.