Hello, I am always wondering how link cloaker sites earn some money because their service is free. I'm thinking about shorl.com, shorturl.com, tinyurl.com and the likes. Thanks.
Its a simple equation: Traffic == Money. If you have decent traffic, there are millions of ways in which you can monetize a website.
You should try them, no they don't use iframes, at least not all and you don't have any popup when you click on of those short urls.