American Airlines reduced their online booking bonus from 1000 to 500 miles for all but the most expensive tickets back in December 2005. Delta Airlines followed suit in July 2006.

Now Alaska Airlines goes a step further and simply eliminates the online booking bonus, effective September 6, for all tickets EXCEPT those purchased with the Alaska Airlines credit card. (via Gary Leff)

I suppose airlines are increasingly confident that their websites are the primary point of sale, and that customers will continue to book their tickets that way. The sites have thusfar been incentivizing customers with the one-two punch of no additional booking fees (a la Expedia, Orbitz, etc.) and bonus miles. Will customers flee if the miles disappear? Alaska’s move is a bold one. We’ll see how it pans out.