Charities certainly love them, but is it more like an unrequited crush? A-listers to Z-listers are rushing lemming-like to any unaccompanied tsunami fundraiser - ironically just as the Disasters Emergency Committee winds down its appeal and NGOs are advising people to give to neglected tragedies elsewhere. Do we really need two separate tsunami charity singles?
The result is that other causes are finding it hard to attract endorsements at the moment. At Great Ormond Street, they are already bracing themselves for the inevitable fall-out of the tsunami fixation as it becomes even harder to secure celebrity backing for other good causes. The 3am crowd don't seem to want to be seen wearing anyone else's ribbon.
We always knew this was a mutually exploitative relationship. PR svengali Max Clifford claims many celebrities don't give a damn, or have a clue, about the good causes they publicly support - half of them only work with charities to boost their image. They can be coldly calculating. One celebrity reportedly scuppered a partnership with a youth charity because his agent advised him that it wouldn't be cool.
Even the holy grail of a full page spread in the tabloids can prove oddly ineffective when the celebrity hogs all the limelight so that nobody remembers the charity or even the cause.
Then there are the train-wrecks of celebrity tie-ups - People for the Ethical Treatment of Animals came to regret persuading Cindy Crawford to back a campaign against fur when she subsequently advertised it. Another charity had to terminate Paul Gascoigne's role in an anti-bullying campaign after newspapers revelations about his less than sensitive treatment of wife Sheryl.
But when they really believe in a cause, committed celebrities can work wonders for charities and sometimes bring almost unknown causes to public attention. Few can have heard of the skin disease dystrophic epidermolysis bullosa before model Nell McAndrew intrigued the tabloids by sporting charity's 'Debra' name on a necklace. Bono's involvement in the Make Poverty History campaign is clearly more than a casual affiliation, and his friends in high places, such as Gordon Brown and Bill Clinton, may prove invaluable to its aims.
Charities need to distinguish the celebrities distracted by passing bandwagons from those with a genuine commitment to the cause. Then they may get as much back in return as celebrities receive.
Mathew Little is a senior reporter at Third Sector