In my experience, it's rare that a single persona would be particularly
valuable. For example, in my current role, there are at least 3-4 main personas
who all have very different motivations, roles, etc...
One of the most basic examples of why you'll probably need at least two
personas, at least if you're selling a B2B product, is that it's very rare that
you are every selling to just one person. In most B2B scenarios, there are at
least two people involved in the purchasing decision process. As you go up
market and begin selling to enterprise, this number can skyrocket to 7-8
people....