If you've got a reseller hosting, or VPS account from a reliable firm, you should also be prepared for downtimes! Remember, your customers don't know that you've taken a reseller account, and don't have the required infrastructure, so the last thing that you want is your customers to realize that your company can't handle such adverse situations.
To tackle such situations, it's recommended to have a back-up reseller account with another host; possibly you may want to host some static websites, low traffic blogs, and small web apps on that back-up hosting account to get the bang for your buck.
So, there you have some of the common hosting issues, and ideas to tackle them, so as to successfully run a web hosting company with minimum hiccups.

