For the past few years, the Pittsburgh branch of the American women's health organisation Planned Parenthood has operated a Pledge-A-Picketer scheme. The idea is simple: when an anti-abortion group protests outside a clinic – as with the 40 Days For Life campaign currently drawing to a close in Britain – Planned Parenthood invites supporters to sponsor the pro-lifers. The more protesters, the more cash. "We put a barometer in the front window that shows the picketers how much they're helping us raise," Rebecca Cavanaugh, a spokesperson, told me. The initiative, which isn't unique to Pittsburgh, seems to grab people's imaginations: first-time donors sometimes walk in off the street, Cavanaugh said, not just because they support the cause, but because they want to get back at the annoying demonstrators blocking the city's sidewalks. "Most of our fundraising is not so fun," she said. "We're mainly talking about the importance of cervical cancer screening and things like that. Whereas this is a little snarky. People respond to that, for better or worse."

Pledge-A-Picket is a neat example of "reverse-incentive" fundraising, something that should arguably play a far bigger role in charity. Helping people financially because you're a nice person is wonderful, of course. But all fundraisers know the risks of "compassion fatigue"; Planned Parenthood's experiences suggest that there's an extra well of money to be tapped if you can harness people's schadenfreude instead. I'm proud to say I care deeply about reproductive rights; I'm rather less proud to confess that I enjoy the idea of people who oppose them feeling irritated or confused. But it's the case all the same, I'm afraid. Plenty of psychological research testifies to the fact that we partly enjoy having enemies; they clarify the world for us, and bolster our egos. So why not channel this less-than-admirable truth to good ends?

This notion needn't be confined to the abortion debate, of course (nor to any particular part of the political spectrum). I dream of an organisation to which I'd pay, say, £10 per month, having selected a set of causes I care about: action on climate change, support for public services, that sort of thing. Then whenever one of a specified group of prominent commentators and politicians spoke out against those causes, a donation would be made automatically. Phillips, Littlejohn, Delingpole et al would face the uncomfortable fact – immensely pleasing to me, of course – that their pronouncements were directly aiding those they denigrated. They might even make fewer such pronouncements. (Not that I'd necessarily want them to, if you think about it. This idea still has a few wrinkles in need of smoothing out.)

The godfather of this twisted but ingenious way of seeing the world is surely the American comedian Dick Gregory, who was one of the first black standups to perform before a mixed audience. Early in his career, when a heckler in Chicago yelled a racist profanity, he responded: "Say that again, please. My contract calls for $50 every time that word is used." Gregory later wrote an autobiography which, over the objections of his publishers, he insisted on giving the title Nigger. It is dedicated to his mother. "Dear Momma – Wherever you are, if you ever hear the word 'nigger' again, remember they are advertising my book."

oliver.burkeman@theguardian.com; twitter.com/oliverburkeman