The main character (who you meet first) has self esteem issues. She stays in her apartment a lot, and doesn't leave. She works as a sex phone operator who talks to people. I think I remember her getting ice cream or something to eat from the fridge as she's taking a call in the beginning of the book. I think she has a certain guy she enjoys talking to as they don't talk about sex, but just about life in general.

There's a second character who comes into the story, as they form a book club or shoe club, where they swap shoes. I think the guy works selling shoes, and may be the guy she talks to on the phone while she's working.

There may be a third character, but I don't remember much about them. Maybe vaguely someone who is married? The group gets involved in solving a murder or crime, and at the end of the book they solve who did it and meet up with them.