Zimride by Enterprise Holdings was an American carpool program that matched inter-city drivers and passengers through social networking services.

[12] Green developed Zimride after sharing rides from the University of California, Santa Barbara campus to visit his girlfriend in Los Angeles.

[15] Noting that 80% of the seats on American highways are empty, Zimmer asserted that ridesharing is "a huge opportunity to create efficiency to save a lot of money and to reduce our environmental footprint.

[20] In August 2010, Zimride announced a $1.2 million round of seed funding from FLOODGATE, K9 Ventures, Keith Rabois, and Teddy Downey.

[19] In 2007, Green and Zimmer launched the first version of the rideshare program at Cornell University; in six months, the service had signed up 20% of the student body.

[2][8][22] Green and Zimmer promoted the service through guerrilla marketing; in particular, the pair would dress in frog suits and hand out flyers to Cornell students.

A driver could post a trip and available seats in his or her car, along with personal details like smoking and musical preferences, allowing passengers to find a match for the destination.

[31] The service only connected people that work at the same company or go to the same school, reducing anxiety and lack of trust which according to Zimmer, was the number one reason for past carpooling failure.

[15] Reuters noted "The Zimride brand promise is to reduce CO2 emissions, lower the annual strain on our transportation infrastructure and help everyone involved save money.

[27] Zimride has partnered with concert company Live Nation and music festivals Bonnaroo, Coachella, and Lollapalooza to hold ridesharing contests that award users with prizes.

[7][37][38] Zimride has also partnered with Jack Johnson, Dave Matthews Band, and Sheryl Crow to provide ridesharing to their events.