Kangaroom, the spare room site quietly shaping up to be a worldbeater - @KangaroomHQ

If you're going to build a new portal, start in a niche like spare rooms, aggregate stock from other sites like Spareroom and build up a loyal following.

Once you have a following, allow people to list.

This is what Kangaroom's founder Jinder Sidhu has been quietly doing. Simple, but very effective.

Have a play with the website: http://kangaroom.net - both browsing and listing property is probably the most slick experience of any property website out there.

This is definitely one to watch.