No, my websites do not fit the scenario you described, but I do generate income from them, and if they are down for even 5 minutes I could lose a sale. Sites do not have to go "down" to update them, it is done behind the scenes.
What concerns me, is the fact that the full suite is portal based with the administrator of the purchased app using the phoneguard.com website.....and it going "down" periodically. Does the phoneguard "app" not work at all when the website is "down"?????
Someone who owns the app should see if it works when the website is down, if it does not, then the website being "down" is a problem IMO. Not being involved in the OPMG IT dept, I dont know if the app is hosted through different servers than the website.