bkshres, hostmonster can handle 2000 visitors at a time. that's the bandwidth cap allowed most to this shared hosting. I've personally discussed this matter with them. I'm not blowing some random made-up stories here.

100 users could literally mean one hundred users hanging on to the site a day same time. Don't really need to be 1 million users per day. I don't know where did you get that idea that if millions visitors visit a day , it turns in to 100 visitors at a same time. It's very weird. Besides, the fact is visitors load depends upon the structure of site as well. Say if the site is serving just around 50-60KB , it really isn't a big load to serve 100 users at a time. Average visitors don't even spend more than 3 minutes per page. Say 1 minute a page. And, if the site is just for information rather than dynamic nature like those news sites, 100 visitors at a time is easy come, easy go.

Now, if you can imagine that all that numbers of visitor not occuring at the same time possibly, guess what , shared hosting today can handle more than 20,000 unique visitors a day. But if the site tends to grow in terms of number of visitors at given time, definitely one needs to upgrade to better dedicated grid servers.. and it'll cost heckuva dohlaaa