If it was the '80s, and I still had a mullet, and sounded a bit more like Jerry Seinfeld, I might start this piece by asking, "What's the deal with Travelzoo (NASDAQ:TZOO)?" It's up 13% today, but that's just the tail end of the story.

The online travel site has been a quick three-bagger over the past month, capping a more than 400% gain for the full year. Basically, the business publishes a website that lists travel specials from more than 300 travel entities and distributes an online newsletter to more than 7 million subscribers. Revenues come from the 300-plus paying advertisers.

There's a lot to be said for the simplicity and profitability of the business model. (Hey, we run something similar at the Fool Travel Center.) Instead of competing with the online travel biz's dueling powerhouses like Orbitz (NASDAQ:ORBZ), Priceline.com (NASDAQ:PCLN), or InterActiveCorp's (NASDAQ:IACI) Expedia, Travelzoo actually gets advertising dollars from places like these, along with airlines and scores of others.

Last year, the firm's revenues grew 83% and net income was up 140%. The latest quarterly numbers, released back in mid-April, show a company that's still putting up some impressive growth numbers. Revenues jumped another 74% and net income climbed 152% over the prior-year quarter. Gross margin was an incredible 97% in the latest quarter, while the net margin is a tamer 18.5%. The firm has $3.4 million in the bank, and no debt.

But does this justify the stock's recent run and its current P/E near 200? I'm going to have to say, "Nope." At first blush, this ought to remind some of you Fools of Taser International (NASDAQ:TASR), another firm with a good business model and strong prospects. But what flies up can come down pretty quickly, too.

Travelzoo's management obviously feels the same way. Not only did it release a statement explaining its own mystification at the increase, insiders have been engaging in pretty aggressive selling over the past couple of months. Some of them have dropped nearly all of their holdings, which suggests to me that they think this is about as good as it will get, for a while. Sure, you might make a lot of money investing with the momentum, but when the insiders start streaming for the exits like bunnies fleeing the lion cage, it's time to re-evaluate your position in the zoo.

Does this online travel site look like a winner? Share your views with Fools on the Travelzoo discussion board.

Fool contributor Seth Jayson owns no company mentioned. View his Fool profile here.