With the upcoming change at Delta SkyMiles to a revenue rather than miles-based program in mind, we took a look at a Reader Meter question set we asked almost 10 years ago, in August 2004. We asked, “How soon do you expect to see a major airline alter its frequent flyer program to be based strictly on revenue spent rather than miles flown?”

By a slim majority, 22.7 percent said, “It will never happen” while a close 21.9 percent said it would happen within one year and 18.9 percent said it would happen within two years.

Bottom line: It took a lot longer than most people thought for this to come about (and we suspect that it took longer than Delta expected, as well). One thing that the responders got right was that Delta SkyMiles was the program they expected to make the change to a revenue-based program, by 27 percent. American AAdvantage came in second as the program likely to make the change, at 20 percent, and United MileagePlus followed at 16.4 percent.