New York; 30 employees; $200,000 in 2011 revenue

Frogtek sells inexpensive mobile software to shopkeepers in Mexico, Colombia, and Spain that connects to their mobile phones and allows them to accept credit-card payments and do inventory management. The company profits by selling data about its software users to food companies and banks. Founder David Del Ser earns a fraction of what his former MBA classmates make, but says his payoff comes in the excitement he sees on new clients’ faces: “I knew mobile phone technology could be put to work to help these small entrepreneurs prosper.” —KK