Some of my thoughts:
I think the call to action and story that you’re telling is pretty solid. I think most people don’t get the value prop down as well as you have their first time around - good work! (Or maybe this isn’t your first time around? :))
Handling 24/7 support seems like something that will be really hard to bootstrap, especially if you’re doing it on the side of a day job? I tend to prefer business ideas that can survive with a 24 hour response time.
Handling custom web apps seems complicated to say the least. Have you thought through that at all? This feels a little more like consulting and a little less like a product business? Still could be a great business though.
Might make sense to have an up-front cost for the (variable) amount of time you’ll need to spend up front reviewing their code.
Do you have any initial customers? This seems like the kind of thing that would be great for you to just pick up a customer or two and start working with them and see how it goes.
I think I saw another service like this recently - might have even been a post on this board - can’t remember. Maybe someone will remember and link it up. Might be good to check that out.
I think I could potentially be a customer for this type of thing. I definitely like the idea of someone else being able to run the show while I’m away. It would be tough for me to justify the cost though during months that I wasn’t using the service - that might be something to think about.
Best of luck man!