Not long ago, Robin Amlot posted a bit of a rant about the charity credit card craze at MSN Money. The rant was on target, as far as it went. If your intent is to donate to a charity, your favourite charity will certainly get far more from your gift if you make the donation directly. Under various charity schemes, your donated loot will actually be worth more to the charity than the amount that you contributed. But that rant rather misses the point of using a charity credit card, doesn't it?

The point is that this is money you've spent anyway. When you charge your purchases on a charity card, you're not paying more or less for your purchases - but a part of that cost goes from your pocket into the coffers of your favorite charity. Amlot's article takes the position that if you charge ?10,000 on the AMEX Red Card - the particular target of the rant - you generate ?117.50 in donations to charity. But if you want to donate the money to charity, the article charges, why not just make a donation of ?117.50 - which, under the right scheme, will actually be worth almost ?200 to the charity - and, the writer adds triumphantly, you didn't have to spend any other money to do it!

Which is, in the real world, a backwards way of looking at things. Let's start with the assumption that you'll charge ?10,000 on your card. Chances are, you won't. Most people don't. But what happens if you charge, say, ?400 in groceries every month on your card - and pay it off each month in one chunk. At the rate of one pence per pound spent, the rate that the AMEX charity credit card uses, they'll contribute ?4 per month to charity - but you're not spending an extra ?4 per month. You're just buying your groceries at the price you'd have paid anyway. And be truthful with yourself - would you think to donate that ?4 each and every month? Most people wouldn't - it's such a small amount. Who could be blamed for wondering what good it would do? But that four quid a month is nearly ?50 per year. Even more importantly, multiply that 4 by another 5,000 people doing the same thing and the numbers start to add up.

Is there profit in it for the credit card company? Of course there is. They count on people's desire to do good to increase their own market share, and increasing that market share means that they make more money even when giving part of it away. Is it good for you? Take the time to compare all the options with the way you shop now and see if it will cost you more to charge your regular purchases. While you're at it, compare credit cards to find yourself the best rates and see if you could make those contributions suggested by Amlot with your savings, if any at all.

Is it good for the charity? Despite the attempt to make it seem that donating via a charity option takes money out of the pockets of those you want to help, the truth is that the charities that benefit get thousands in donations that no one would have thought to make in another way. Those four quid and 20 pence here and there add up - to the tune of ?380,000 from Barclaycard in 2004.

In short, when you compare and choose a charity credit card, you are using your choice to direct donations to one of hundreds of charities in need - donations that most people would consider too insignificant to bother with. How could that be bad?

If you're in the market to apply for a credit card, you can compare credit cards and all charity offers at good comparison websites, where you'll find the best deals listed and easy applications for dozens of the best credit card offers in the UK.