Another thing to remember: When Star Wars came out, the idea of home video was still in its infancy. Even by the time ROTJ came out, it was still not THAT common for people to have VCRs in their homes.
If you saw a movie you loved, you had to go watch it in the theater again. A few years later, you MIGHT get to see it on TV, if you were home when it came on and your parents would let you watch it instead of whatever they wanted to watch.
But look at the Star Wars playsets. You can re-imagine the entire movie by acting it out on your bedroom floor, if you have enough doods and all the different ships and vehicles. So right after you saw Empire for the first time, you NEEDED that Snow Speeder and one of the AT-ATs. And a tauntaun and a flammin-with-the-flimflam droid.
It was fucking perfect.
