LED

Ok, so I was just at Canadian tire doing some Christmas shopping when I stumbled on Replacment LED lights for tail lights. I figured what the heck, buy one and try it. I plugged the light in pressed the brake. The brake lights flashed and then nothing. The tail lights would stay on, but not one single brake light. Turns out, the bulb blew the stop fuse not allowiing the lights to go on. This was quite a surprise as LED's run on less electricity then standard bulbs...don't they? Any help would be appreciated