The point about e-cards is that they're great way to manipulate people into clicking on a malware link. Thanks to the number of compromised Microsoft address databases out there, it's easy for a spammer to fake the sender, and it's easy to disguise where the link goes so that at least a large proportion of recipients will be fooled.

Fire off a million "Happy Birthday" cards and you'll get about 3,000 recipients on their birthday. If one in ten of them gets suckered into clicking on your malware link, that's 300 more machines for your botnet. And everybody has Christmas at the same time.

Though my original reason for never clicking on them was that they always came from people who I know were too mean to buy a stamp.