In previous companies, as well as the one I'm working with now, I hear a common objection: if everyone has your product how is this a competitive advantage. Good question. And there is an equally logical response.
Think about it this way. Do both companies sell exactly the same thing and produce/market it in the same way? Of course not; doesn't seem logical and if that were the case then I'm sure there would be lawsuits. What software companies produce is process and service. To state more clearly, the way you use (process) the software in your daily life or business is the service. It is the competitive advantage. Thus, the advantage doesn't come from just having the software but instead, how you use it.
The picture above kind of illustrates my point. Is it a face or a vase? Surely most of us know the optical illusion going on here, but the point I'm trying to make with this picture is how you "process" the image; what you are focusing on (service).