over and over again, or through what we call paid growth meaning we reinvest the revenue from past customers into advertising, or retail store fronts or whatever is needed to get the new customers. and so that is the mechanics of sustainable growth. it has that feedback loop quality where customers themselves are providing the resources that allow us to get more customers. >> and it's great, because a lot of people spend a lot of time getting new customers when really they're growing because of their current customers. >> exactly. >> and so they're wasting money on these new people in some way. all right, eric ries, i wish we could talk for a half an hour more, but unfortunately, it's the end. but everybody should go read your book "the lean start up"because it's very helpful. >> really appreciate it. thanks for having me on. >> still to come, small business owners tell us what they think about the president's plan to create jobs in this country. and we'll answer a question on pricing from the owner of a spa for dogs. plus, today's elevator pitchers have a solution about what to do with all of your bags when you still have more shopping to do.