Interesting ! But celebrity investment doesn't guarantee anything apart from a lot of initial press and traction,do they ? Those startups continue are vulnerable to the same failures like any other. Ashton Kutcher invested in the social flirting app which failed to take off , Leonardo Di Caprio invested in Mobli (which isn't big right now either) and a few others. If there is no alignment of the celebrity's existing brand & image to the startup they invest in , the value seems to be strictly initial publicity.