But ChildLine is bucking the trend by launching a search for 50 new volunteer ambassadors who will be recruited from the general population rather than the pages of Heat or Hello!
The scheme has been launched at a time when ChildLine is in financial crisis. It is hoped that it will enable the charity to reach parts of the country where it feels it lacks a presence and raise much-needed funds there.
Daniela Slanickova, project manager of the scheme, explains: "We have 11 centres around the country, and we were getting calls from people who wanted to volunteer for us but lived too far away from one of these.
"The idea of the new ambassadors is that they will help raise awareness about what we do and fundraise by building relations within their own communities."
However, the ambassadors are not intending to replace celebrity patrons. "We don't want to replace our celebrity supporters, because they do a valuable job, but the volunteer ambassadors will be the public face of the charity," says Slanickova.
The scheme echoes a recent project in which animal charity PDSA recruited volunteers to give talks about the charity - but ChildLine will ask participants to be more proactive. All the ambassadors will receive training, and a mentor from ChildLine's fundraising team will support them.
They will be expected to give talks, but they will also attend events such as cheque presentations, where they may be required to talk to the media.
Slanickova says: "They will be briefed to answer straightforward questions, but if they get any questions that go beyond their remit they will refer the matter to the press office."
ChildLine is looking for volunteers who can spare a few hours a month and are confident enough to tackle public speaking. Slanickova adds: "We recruit volunteers from all walks of life and hope to do the same with our ambassadors."
Anyone interested in becoming an ambassador can call 0870 336 2940 or email email@example.com.