A virtual private server is a term to describe a virtual machine. Otherwise known as a cloud server, VPS provides the power and functionality of having your own server at a much more accessible price. Purchasing a VPS service means total use of the machine with root access, dedicated CPU and RAM.
Do you have multiple websites?
Shared hosting usually allows for sub-domains but hosting companies can sometimes be picky about you having more than one webpage. Companies like ASPnix allow you 5 -100 websites per shared hosting account but others can be pretty restrictive. VPS hosting will provide ample disk space for all of your data and websites. With dedicated RAM and CPU you know that you wont have problems handling massive data or traffic.
Are you expanding as a business?
With more business comes more traffic and with a shared hosting environment you may find that data and processing power are not up to your new expectations. VPS offers you a flexible way to continue to grow.
What kind of content will your site host?
When upgrading to dynamic content make sure that you have enough resources. Dynamic content will soak up all of your system resources like a sponge and if you are still using entry level shared hosting you will eventually need a lot more than what you have.
Is your site slowing down?
Web hosting companies want to treat their customers fairly and if you require a huge amount of resources then you may end up seeing yourself slowing down.
Do you have added security and backup a concerns?
There are certain security limitations with a shared hosting account that don’t apply to a VPS. Companies like ASPnix and others make regular backups to insure your data is safe as well as utilize a hardware firewall to add to your security and give you 24/7 tech support. This can be critical if you are in need of added attention to security and have critical data on your server. In the event of some kind of an emergency you can always call on someone from their staff and get the help you need to identify and solve any issue.