Jeremy Hobson: Today Zipcar is going public. The car-sharing company which is popular among city dwellers and college students was founded about a decade ago. And it’s grown to more than a half a million members since then.

Marketplace Steve Henn reports.

Steve Henn: Zipcar has ironic ads, cool cars and a growing customer base. It even bought a competitor in London. But there’s one thing Zipcar doesn’t have: profits.

Michael Millman: Yes, after 10 years I would think they should have shown a profit.

Michael Millman is a rental car analyst and isn’t convinced that Zipcar will succeed. But Kathy Smith is more optimistic. She researches new IPOs at Renaissance Capital.

Kathy Smith: The company is making money in the early markets that it has started.

If you break it down, the company is turning a profit in Boston, New York and Washington D.C. And Smith says Zipcar’s plowing that cash into new markets.

Smith: The reason it’s not making money is it’s expanding very quickly.

Smith thinks Zipcar could spark a new multi-billion dollar industry — but even she expects bumps in the road.

In Silicon Valley, I’m Steve Henn for Marketplace.