The proliferation of start-ups on the web can make it incredibly tricky for an advertiser to know where and how to allocate a budget. For every Facebook and Twitter, services with millions of users and undoubted critical mass, there is a Joost, or Google Wave - services launched with the maximum of fanfare and the minimum of audience buy-in.
Remember when industry analysts started to loudly proclaim the death of TV commercials? Ten years after TiVo sprang onto the scene, TV is not only still here, it is enjoying a renaissance, having been reinvigorated bydigital technology as opposed to cannibalised by it.