Have you signed up for JetBlue's frequent flyer program? If you haven't, you are missing out on some great deals.

The airline emails frequent promotions available only to members of TrueBlue, such as the one we just received this morning.

"It's never too early to start planning an exciting, end-of-summer or fall adventure. Book now through June 26 for travel between September 3 and October 31, 2008 and save 10% each way!

Just click here and enter Promotion Code OCTJET2 when you select your flights. Remember, you must click through this email to take advantage of this offer and travel must be completed by October 31, 2008."

Note, however, that you have to click through from the email to get the deal. Or so they say. However, we think that if you just click on this link, and enter the promo code, you'll get the 10% off. Try it and see.

But wait there's more: use promo code OCTJET and you'll get $10 off each way on any JetBlue fare using the same link.

Obviously, the $20 off roundtrip code is best for fares under $200; over $200, use the 10% off prom code.

So don't hesitate to sign up for frequent flyer programs and the airlines' special offer email lists. Airlines are bypassing traditional sales methods, preferring instead to develop a direct relationship with their customers by using promo codes and fare widgets.

That's why, frankly, all these new computerized, high tech fare prediction and comparison tools and web sites don't quite have the full picture (besides the fact that they don't take Southwest Airlines into consideration).