I am in the same boat. I currently am hosting my site in a hostgator (shared environment), which is fine for the time being since I do not have a significant load. I am concerned that when I need to scale that I would quickly out-distance the limitations on a shared environment.
In the near future, I hope to do some load testing (on my shared-hosting environment) to nail-down the exact number of requests and users that can be simultaneously using the system and where those limitations fall.
I have been looking for dedicated or vps environment for when I have to scale to support such a load.
I have had good luck with HostGator and RoR (in a shared environment) and that is why I am primarily looking at them for a VPS or dedicated environment when the time comes. Their tech support has been helpful, timely, and knowledgeable.
If you are going to signup for a HostGator service/product, please use my affiliate account (http://secure.hostgator.com/cgi-bin/aff
*** I am not advocating you choose HostGator, choose what is best for you, but if you are going to, I would appreciate the referral! ***
HostGator Shared Hosting Limitations:
- You are allowed a maximum of 25% CPU usage limit for 90 second burst.
- You are allowed a maximum of 25% CPU usage limit.
- You are allowed a maximum of 25 mysql connection simultaneously.
- You are allowed a monthly limit of 250,000 *inodes.
*Even though we do offer unlimited quota and bandwidth for our webhosting, there are other limitations set for the package, no more than 250,000 inodes, every file (a webpage, image file, email, etc) on your account uses up 1 inode.
Hope that helps.