The transparency of raw airline data in recent years has been hugely important for our ability to secure the lowest fares and build the best itineraries. ExpertFlyer.com has been a pioneer in that endeavor, and now it has taken an extra step by showing government, military and other fares that have long been a mystery to most travelers.

I first began using ExpertFlyer soon after the website launched in 2005, and was happy to pay the $100 annual fee because it has helped me save thousands of dollars. Last year, when I left the Washington Times and started teaching seminars, I naturally decided to use the site in my classes — and I received a complimentary subscription. In the interest of full disclosure, ExpertFlyer also donated $1,000 to the book tour I’m currently on. That said, I’m not at all obligated to promote the site in this column…