Depends on your definition of sell I suppose. By that logic all of our interactions with people are 'selling' to them. When my boss asks me how many hours I've got left I'm 'selling' the 12hrs I need. When I hold open a door for an old lady I'm 'selling' that I care about old people. When I notice my SO is down because of family issues and I make her a nice dinner, I'm 'selling' that I'm a nice guy.
You can certainly frame life that way, but it doesn't feel very nice, to me anyway.
Yeah, it's one way to interpret things - not necessarily right or wrong.
In a sense, we, ourselves, are the biggest targets of our selling efforts - for example, taking certain actions that are consistent with our self-image while avoiding actions that contradict it - in an effort to maintain a perception of our "self" as a consistent entity with consistent values over time.
You can certainly frame life that way, but it doesn't feel very nice, to me anyway.