Most people do not give enough consideration to calculation of their data transfer limit, although it is an integral part of their hosting package. They either take the first advise that is given to them, or just chose a random option and then upgrade/downgrade towards the end of the month if the actual figures are highly inconsistent with their estimate.

Possible causes of data transfer excess could be:

• Your data transfer limit would increase if the number of hits to your package has suddenly risen because of some application or service which you have newly started, and have not altered your data limit appropriately to provision for the same.
   
• As the popularity of your website increases (number of hits increases), the data transfer increases too.

Due to this, it is essential that you anticipate your requirements well and provision for data transfer accordingly. Also, you need to monitor your web statistics regularly to get details about your actual usage, and hence provision for data transfer limit in a more effective manner.