Every company wants matching, professional photos of its people, and nobody wants to leave the office to get them. One San Francisco photographer started emailing coworking spaces and shot 1,500 sessions in his first studio year. The studio is the client's own conference room.

Plenty of adults want to learn bluegrass guitar, and most towns don't have a teacher who plays it. One Colorado guitarist runs an online club for $25 a month with about 300 members. The trick is how narrow he made it.

Every used car on a dealer's website needs a full set of photos before anyone clicks, and the lot refills every week. Dealers pay per car to make it someone else's job. One Sacramento photo company grew to nearly 50 dealerships and sold this year.