That's quite neat - would be useful to those of us looking for property in London.
But, and I'm sure you've heard this from other people, the biggest problem with finding properties in this town is that basically every single property shown on any website has already been rented. I'm a bit worried that your site will just be a nicer, cleverer interface to show me a whole lot of flats that aren't on the market any more.
Well, first, I applaud any efforts to improve/disrupt/whatever the rental market in this town, which is just comically awful. This sounds like it'd be exactly the kind of thing I wanted the last time I was looking, but ended up having to give up on at the time.
But - I don't actually see a solution there. You've got a very apt description of the problem and of what the solution would look like, but I do think there's a big leap from identifying those to actually going to something that works. The critical point to get past is of course actually having a number of interesting properties listed on your site, which requires overcoming the awkward network effects inherent in that market which the real estate agents obviously have a massive interest in perpetuating.
But don't let me get you down - I'm a bit cynical about this after my last experience flathunting, but everyone I speak to hates the system at the moment and would love something better. There are a ridiculous number of real estate agents in this town which implies there must be an awful lot of money in the market - ample room for someone to seriously undercut them while offering everyone involved a better deal.
But, and I'm sure you've heard this from other people, the biggest problem with finding properties in this town is that basically every single property shown on any website has already been rented. I'm a bit worried that your site will just be a nicer, cleverer interface to show me a whole lot of flats that aren't on the market any more.