This is a UK-based classified advertising site, offering listings of real estate, items for sale, personals and so on. Which is all very well, except that some genius had the brilliant idea of not using ordinary web links for ads, but instead doing it all in Javascript. When you click on an ad, it executes a piece of javascript which changes the current window's location for you. This means that it is impossible to open an ad in a separate window or tab; you can only view Loot in one window at a time, linearly going from ad to ad and backtracking as need be.
I have no idea why anybody could have thought that sort of user-hostile web design is a good idea. It's not to encourage people to pay (paid users get the same interface), it doesn't give the site a slick, Gmail-like interface (it's just a normal web site, except that you can't easily view more than one thing at a time), or otherwise contribute to the user experience (unless, perhaps, the user is a submissive masochist), it doesn't even seem to aim for the holy grail of Protecting Valuable Intellectual Property. The only possibilities I can think of are: (a) that they were betting that, by slowing down user browsing of their site, they could eke more time-limited ad-viewing tokens out of their users, and that no competing website would steal their customers by offering a less annoying experience, or (b) that whoever designed it just wanted to show off their web kung fu ("Look mum, Javascript!")
Annoying gits.
Believe it or not, there is a theory among (some) advertisers that it is more effective to 'get in your face' and annoy target audiences. This is why you have ads with people in loud clothing shouting at you.