Sometimes even a race car has to slow down.

Zipcar (Nasdaq: ZIP) stumbled in its latest quarter. The leading car-sharing service missed Wall Street's top- and bottom-line targets for the second quarter. Guidance for the new quarter is also short of where the prognosticators were perched.

Sharing of big-ticket assets is a trend that isn't going to go away. The high costs of auto ownership make Zipcar and other auto-sharing services smart decisions for infrequent drivers. However, Zipcar needs to work on its engagement.

Subscriber growth is 21% higher than it was a year ago, but revenue climbed only 15%. In other words, the average user for Zipcar's 731,000 subscribers is sending less money to Zipcar.

A great model isn't always a great business.

Briefly in the news
And now let's take a quick look at some of the other stories that shaped our week.

  • Jamba (Nasdaq: JMBA) has nearly doubled this year, but it took a step back after posting a smaller adjusted quarterly profit than the market was expecting this week. Blend harder next time.
  • Sirius XM Radio (Nasdaq: SIRI) continues to beef up its content with artist-centric programming. Linkin Park and Latin music sensation Juanes are two popular musical acts that have been added to the satellite-radio provider's exclusive content.
  • LivePerson (Nasdaq: LPSN) posted a quarterly profit that fell woefully short of Wall Street expectations. Revenue growth was still a robust 21%, but LivePerson may want to strike up a live chat the next time it's online to see whether it can get some advice on improving its margins.

Moving on
Now that you've had a glimpse of the past, let's delve into the future. We're now just months away from the 2012 presidential election. Do you know the stocks that could skyrocket after the polls close? A new special report has all of the winners. It's free, so what are you waiting for? Check it out now.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.