Readers of this space know that I've been waiting quite a while to see some more robust growth in passenger traffic at Mexican airport operator Grupo Aeroportuario del Sureste, known by the acronym ASUR (NYSE:ASR).

The latest traffic figures boast some crazy-looking (near 60%) gains, owing to the fact that this year's traffic is being compared to last year's storm-battered totals.

So, to get a better gauge of just where ASUR's traffic has been heading, I've been comparing the 2006 figures to the 2004 figures. And that's where we see a good boost for the December numbers.

Total traffic reached 1.306 million, a 58.5% increase over December 2005, and a nice 13.5% boost over December 2004's 1.150 million passengers. Traffic growth was especially strong at Cancun, which grew 15.3% from December 2004 to 2006.

That, of course, is vitally important, because the tourist traffic at Cancun is worth more to ASUR. Tourists, especially international tourists, tend to drop a lot more cash when they're on vacation, boosting ASUR's commercial-revenue stream -- the one that's not under the thumb of the government. (International traffic at Cancun more than doubled for the December period from 2005.)

As I've often stated, I love these airport businesses because they have great leverage and can send a large portion of increased revenues straight to the bottom line. So while the markets continue to be manic about all things airline, alternately punishing and rewarding shares of Continental (NYSE:CAL), Southwest (NYSE:LUV), JetBlue (NASDAQ:JBLU), UAL (NASDAQ:UAUA), and even floating dreck like Northwest (NWACQ.PK) and Delta (DALRQ.PK), I'll take the airports, thanks.

I don't need to worry about fuel costs. I don't need to pray for a buyout. And I'm buying into a real live stream of cash flows -- much of which is paid out in dividends.

Seth Jayson recommended ASUR shares to Fool readers in March 2006, and they've returned 28% since then. He's a part of the Global Gains team, which looks for other great investments flying under the world's radar. A free trial is just a click away.

At the time of publication, Seth Jayson had shares of ASUR but no position in any other company mentioned here. View his stock holdings and Fool profile here. JetBlue is a Stock Advisor selection. Fool rules are here.