How Do I Tell How Many Pages A Web Site Has?

Not my own web site, but others on the internet. I’m trying do do some market research on a niche I’m working on that involves building a web site, that would basically kind of compete with other large sites that come up in the search engine when searches are done on this topic. Is there a way I can tell how many pages those sites have to get an idea of how big these sites really are?

See original post by william@amwso.com