Story
I'm doing The BUPA Great North Run in aid of St John Ambulance. We (me and the other ~44,999 volunteers) give our time to treat ~200,000 casualties a year at everything from school fetes up to stadium events, the London Marathon and emergencies like the 7/7 bombings, for anything from cuts and grazes up to broken bones and heart attacks - but we can only do that with proper training, first aid kits and other medical supplies, defibrillators (aka "heartstart machines") and ambulances. We're entirely reliant upon donations to achieve this.
I've pledged to raise half a grand for SJA, and if I fall short of legitimate sponsorship I'm planning to make up the difference by mugging grannies, selling crack in school playgrounds and stealing sweets from babies[1]. Thing is, £500 is a whole lot of pensionless grannies, crack-addicted kids & unhappy babies. You wouldn't want that on your conscience, would you? So please, think of the grannies and help me raise as much as possible legitimately.
In return I'll do the run (a half marathon; 21 km/13 miles from Newcastle to South Shields) as fast as I can[2] without passing out from the overpowering cloud of acrid sweat from 49,999 other runners, and I'll promise[3] to be there to save you next time you mess yourself up.
Deal? Deal! Thanks for your support! Now give generously!
[1] Stealing sweets from babies is just for my own amusement; St John Ambulance can't make any use of them.
[2] I'm aiming for 1h35, but it's my first half-marathon so who knows.
[3] Not true.