First off don't force video on anyone, they should chose to view it. There are a couple of ways to stream (buffer), use a progressive stream or stream it form WMS. That way it will buffer and not load the whole file.
Next encode your video - 50 megs will put up a whole hell of a lot of video on thye web. I don't know what you're showing but sometimes quality isn't as important as getting the point accross - example - this is a 4 meg video -
http://www.forextips.com/INTRODUCTION-FOREX-video.htm
WM encoder 7 still does a better job of encoding for the web (if you already put a newer version on its a process to go back, but well worth it.
Do a screen capture of your video using mwe 7 and lower the audio to mono, and cut your fps. Play with it and reduce the size.