Insane Download Speed

I don't get it. I use dialup and yet I am right now downloading a file at 20-40 kilobytes a second. The speed of the downloading is slowly fluctuating between the two, at times reaching even as high as 70 kilobytes/s.

Its a 6 megabyte word document, is it because its text so the modems can compress it so easily? Because I literally just downloaded a 6 meg document in a couple minutes!!!