If you operate an e-commerce site, one that sells products to consumers online, you can also supplement your site's income with AdSense.
AdSense can be "additive" to your e-commerce sales, as opposed to taking sales away from you. This is because not all of your site's visitors are going to buy something from you. They might just want to browse around, or perhaps buy something from you at a later date. You can use AdSense to monetize these visitors.
There's a woman who breeds lizards and tortoises and sells them online. She runs an e-commerce site called "Herp-titude"...
She asked me if I could help her earn some extra money by running advertising on her site. So, I suggested using AdSense since it runs automatically. (I should have referred her through an AdSense referral link, but I forgot about that, damn!)
So I explained to her about AdSense, which she knew nothing about! It's interesting to know that there are still so many website operators that don't know about it. She got her website approved, and I made some recommendations on what creative size to use, what colors to use, and where to place it.
She says she's earning a couple of dollars a day with AdSense, and her e-commerce sales have not dropped. Even if she's only earning a couple of bucks a day, that still equates to about $60.00 a month, and it's additive.
I advised that placing the AdSense creative within the body of her content would prove better, but being she's never ran ads on her site, she wanted to just try this for now. I also went on to recommend incorporating a blog within the site to publish news and tips, to create search engine food and increase visitors. She wants to do that also, but I got the sense that I was overwhelming her.