Awhile ago a variety of celebrities declared themselves dead, not Tweeting and such until enough donations to fight AIDS came in. Despite this being for a good cause, it was a failure at the time as noted. The site now appears to have donations up to par, but it sort of looks like . . . well judge for yourself (http://buylife.org/).
So why didn't this death-on-social-media have an immediate influx of donations? I think part of it was the odd, kind of self-centered method of raising funds and the tastelessness of it. The other part was that the celebrities stopped being celebrities.