Put yourself in their shoes, and try to do your best to write what would make them feel comfortable and good about your product for long enough for them to get out their credit card.
Regardless of the size of your company though, it's good to keep in mind that some people are going to be very sensitive to stability when making purchasing decisions, especially if they've been burned in the past by a service that suddenly stopped working. The people who don't care about this, won't care anyway, so for them it doesn't matter what you write.
So I'd be erring on the side of talking about stability, even if you are a one man shop. Especially if your product is still in the early stages and lacking the polish of more mature products.
So perhaps instead of: "After working for 4 years as a server administrator for some medium to large websites and after having a lot of trouble with existing monitoring solutions I decided to build my own."
Maybe something like: "TagBeep was developed in response to a gap in the market for a professional yet simple tool to track website uptime.
Our years of experience in server administration for medium to large sized websites provided us with unique insight into designing a powerful application that takes 5 minutes to set up, and helps you keep your sites up and running 24 hours a day."
Also, while you're clearing in active development and doing a lot to improve your product, I'd hesitate before broadcasting this process that to a small business owner who might not be familiar with the development process, and who is in the decision making phase while looking at your About page. I'd be moving the "Whats Next?" stuff to a dev blog hosted on tagbeep.com/blog.