Shared web hosting service refers to a web hosting service where many websites reside on one web server connected to the Internet. This is generally the most economical option for hosting. When you are using a shared web hosting you must remember that you will also be sharing the IP address i.e thousand of websites will be hosted on one IP address. If your shared hosting IP address has thousand of spam website then it might certainly affect your SEO.
Shared web hosting is not for websites with a huge volume of traffic. As I’ve seen with many shared hosting providers the number traffic a shared hosting provides is up 1500 per day. Most of the website hosted on shared hosting is for information purposes only.
Traffic usually is not a problem on shared hosting but there is a limitation to the unmetered bandwidth provided by the hosting provider. The only problem you may encounter is RAM and CPU restrictions. But if your application is written correctly it could operate well with these limitations.
Theoretically, I think shared hosting with most services could support about 60 users per hour max efficiently if your users all came one or two at a time. This would equal out to about 1500 users in one day.
Most of the shared web hosting supports 100 – 200 entry process. What is the entry process? The entry process is the number of scripts like (PHP) running at a single time, when a user visit you website how may PHP script does it requires to run and render the website to the end user is an entry process.