We do not have a limit to the number of visitors. However, there is a physical limit our network can handle.
There is no way to determine the maximum number of visitors your site can sustain. Each site is different and the amount of traffic you can handle will depend on the resources each visitor is using. A very efficiently coded website that uses few resources per visitor would allow a large number of visitors to visit your site at the same time, while a poorly or inefficiently coded website may become a resource hog with only a few visitors on simultaneously. How many visitors your site can handle is largely determined by how your site is coded.
If you are using a content management system (CMS), you may want to utilize some of the tips in the following articles to increase the number of visitors your site can handle.
You can view your site statistics, like the number of visitors and which browser they use. Your cPanel includes a statistics program called AWStats.
What about huge and unexpected spikes in traffic?
Basically, if you spike the server too hard or for too long, you can be suspended for taking the resources from your fellow shared server users. If you don't want this to happen, you need to move to a dedicated server.
But I thought it was unlimited?
Depending on the type of plan you have, certain things on your account are indeed unlimited. For example, shared accounts give unlimited disk space and bandwidth. When companies say unlimited, what they mean is that they do not meter or limit you on that item. But just because you can have an unlimited amount of something does not mean it is physically possible to consume an infinite amount. Unlimited does not mean infinite.
For example, when you go to an all-you-can-eat buffet, you can eat an unlimited amount of food. However, it is impossible for you to eat an infinite amount of food because of the size of your stomach, the number of hours the restaurant is open, how much food is physically available, and the fact that you cannot share your food or take it home with you. Certain rules for the buffet are put in place so one person does not come in and take all the food from all the other paying customers.
Similarly, it is not possible to use an infinite amount of the server since there are other limits in place, like how much CPU you can use at one time, how many processes you can have open at one time, how many emails you can send out in an hour, etc. Certain rules are in place to make sure one person does not use the entire server on a shared account, preventing other customers from using the server.
If I need to handle more traffic, what should I do?
Shared, reseller, and VPS all handle the same amount of traffic. My best recommendation is to upgrade to a dedicated server, or a more powerful dedicated server.