People don't use protocols—people use tools.

uhh,ok.. and tools can implement protocols. I think the gp's point was that many of these tools don't lend themselves to interop and portability, important things to factor in when evaluating a tool.

EDIT: I don't know if his point really applies here with these saas tools. From my experience, these usually offer at least a standard way to export your data in case you want to jump ship later.