Have you ever watched someone walk into a business event and start circulating with the obvious intention of giving away as many business cards as possible? It’s a little like marking territory, hit one and move on to the next. Not something I’d recommend.  The best time to give someone your card is when they ask.

Sometimes you’re having a terrific conversation and you’re sure that it would be mutually beneficial to keep in touch. If you want to give someone your card, but he’s not asking- then ask him for his card.  Usually people respond in kind. The rules are still the same, don’t do it indiscriminately, don’t do it in the first 10 seconds of conversation, don’t presume. It doesn’t always work, but it’s worth a try. 

If you want to give your card to someone, ask for theirs. At the very least, you can use it to follow up.