[justinmares]

In the book we talk more about offline channel tracking, but basically you can tie them to online activity (e.g. discount codes, unique URLs, etc.) or via the "how did you hear about us?" questions.

For beating chicken and egg problem, generally you want to figure out which side is more difficult to get (demand or supply side) and then think about what traction channels work to acquire people on that side of the C&E problem. Happy to chat more over email if you'd like specific help.