Thus Jane Jacobs describes the growth of the Japanese bicycle industry in The Economy of Cities. The idea was that a local industry could grow up around a popular activity, and then become the basis for further economic growth (as it did in Japan).
Maybe people in Portland have been reading Jane Jacobs, or maybe it's just common sense, but according to this video and accompanying article, a nascent industry has developed in Portland around bike usage. The city currently has 125 bike-related businesses, mostly small and locally-owned, covering everything from repair and custom bike building to accessories and consulting. And it is a growing industry.
The catalyst for all of this economic growth was a decision by the city to invest in designing the city for bikes. Officials say they have spent some $20 to $25 million on bicycle infrastructure over the past few years, and have plans to spend another $24 million to significantly expand Portland's bicycle network. The city also supports local bike-oriented businesses. If this seems like a lot of money to be spending on bikes, consider that an average highway interchange costs between $10 and $15 million, not including planning costs and the cost of buying up the land on which to build.
Bike-friendly planning creates many opportunities, and not just economic. Local artists have been given the chance to design unique symbols for bike lanes, giving a human touch to the traffic markings. Check out this article on the artists; here a some examples of their work.