The owner of the websites should have some of the basic knowledge of what hosting companies’ mean by "data transfer". This is the main factor that affects the cost, so user should make the decision of choosing web hosting with the proper understanding.

General idea of data transfer:

Transfer means "Bandwidth" or "traffic". Actually it is the amount of information (in bytes) transferred back and forth from visitor's computer to the server where one’s domain is hosted. Here are some of the examples of data transfer: someone filling out a form and submitting it back to user’s web site; a visitor downloading images, audio or video, or just surfing user’s website. Every time a web surfer visits one’s web pages, data is transferred from the server where his/her website is hosted on, to their computer. If one desires that lot of people to "hit" his/her site, then he/she should have plenty of data to be transferred!

It is up to the one’s host to include or not to include FTP as data transfer. If one’s host include the FTP as the data transfer, then it may be dangerous to his/her data transfer quota. For an example, one can you make regular database changes that require downloading, making changes, and then uploading an entire database back to the server. This is only an example as there is many of the web sites implement CMS (Content Management Systems) that permits the database editing through administration control panels, so as to minimize the quantity of data transfer.

Getting the sufficient amounts of data transfer through good online hosts is no more a challenge rather one can have it easily. This means that most small Ecommerce storefronts are now able to handle plenty of traffic having the low hosting costs, so now they don’t need to worry about their running out of their monthly bandwidth quota.

Calculation of Data Transfer:

Following is the example of calculating data transfer for a hypothetical web account.

Say if one has an account that allows 7GB of data transfer per month and his/her average file size transferred is 100KB (the size of 6-7 page views). This being the case one can run 73,400 files per month, or 2446 daily, over 30 days.

Here's how one get that number:

1.) First of all convert the average file size from KB to Bytes: 100 X 1024=102,400

2.) Secondly determine the number of bytes in 7GB by the number of bytes in 1 GB – 7 x 1073,741,824 =7,516,192,768

3.) Thirdly, divide the number of bytes in 7GB by the number of bytes in one’s average file size: 7,516,192,768 /102,400=73,400

This means that visitors have to hit one’s site and transfer roughly 100 - 100KB files every hour 24/7 for a month before he/she would use up all his/her bandwidth. Possibly this may be extreme, unless he/she is big in actual terms. For the meantime, rest assured, there are number of high-quality hosts that include lots of bandwidth (50 GB) monthly for between $5-10 USD. For running small Ecommerce sites smoothly it is quite enough. At any case if one’s web site is getting traffic of this amount, then he/she does not require this article as he/she can probably afford his/her own web hosting company! So best of luck!!