Yeah, I know it's kind of an open ended question. There are many factors such as internet connection speed, etc. However, generally speaking what is too big of a file in WMV. I've compressed a video that is 18 minutes long to be played back from my website in WMV and the total size is 178 MB. Do you recommend I lower my setting and drop the file size?
If you're coming from an http server (progressive download), break it in to smaller chunks otherwise people will have long waits while enough file buffers to play. If people can't sit through the whole thing they'll have to start over again on the next visit. I'd break it in to three parts. I finde a data rate range of 300kpbs to 800 kbps reasonable depending on the the typical DSL/Cable speeds in the area you target. File size is important if you're nearing your size alotment or monthly throughput limit.