For a long time, there were niche communities of “lo-fi” camera enthusiasts: people who shared photos taken on old cameras that had interesting ways of filtering shots. The iPhone app Hipstamatic popularized lo-fi filters, selling over 1M copies. Because Hipstamatic lacked sharing features, many users took pictures with Hipstamatic and then shared them using other apps. Then came Instagram, which combined lo-fi filters and easy sharing. Instagram has been downloaded 15M times and has apparently crossed over to mainstream users.
Instagram built a product devoted to a job that users were previously performing improvisationally using multiple products. This is a common pattern for popular software and services. Before Twitter, people shared interesting links through email or “link round-up” blog posts. Tumblr’s short-form blogging/re-blogging was inspired by an “unintended” use of long-form blogging platforms like WordPress. Before Foursquare, power socializers sent out mass text messages with their locations (in fact, Foursquare’s predecessor Dodgeball did exactly that).
New startup ideas are all around you, in the improvised behaviors of people you know. It takes a keen product eye, however, to notice these improvisational behaviors and recognize which ones are worthy of being developed into standalone products.