All web hosting services, whether they offer business web hosting or some cheap web hosting even, give due importance to bandwidth. As a user of cheap hosting or even the best web hosting client what you need is a decent rate of date transfer. That ultimately decides how much data can be uploaded on your website. That also determines how much data can be transferred from your webpage to the people visiting you site.
Deciding how much allowance you site needs can be a bit too tricky. But if you want to know, all you need to do is take a good, long look at the actual, real time data transfer which your site creates. That will give you an idea about the needs of your website as far as the bandwidth is concerned. Consider the following example. For a website of five pages, each being a size of 50 kb, it means that each user visiting one page on your website requires 50 kb to see one page on your webpage.
If your traffic increases and you get like, a hundred visitors every day who browse all five pages on your website then you need 25,000 kb per second or 24 MB per second to be exact. That is for a single day. If you get that kind of traffic 30 days a week then you multiply 24 with thirty because that bandwidth is what your site will need every month then. But do not forget that this bandwidth is only what is being consumed by the visitors. You will need extra kbs for other applications like emailing, FTP and of course, uploading.
Now that you know what bandwidth is and how it works, you can decide be in a better position to decide the bandwidth and pick a website hosting service which serves your need best.