In the event that you host your websites on a dedicated hosting machine, you would expect that they will perform very fast and that the access speed to them shall depend only on the Internet connection of the website visitors. However, this will not be the case in the event that the server has bad network connectivity or uses a network card, which just can't deal with high volume of traffic. If this is the situation, it shall take a very long time for your websites to load if a lot of people open them at the same time or visitors might even see error messages. As a result you may lose visitors as in all probability many people will never return to your site if they have experienced issues or slow loading speeds. This is the reason why you should pay attention to the network components of any new server you purchase and not just to the main hardware which includes Processor, Ram memory or hard drive.