OK, I have a theory here, and only the great and powerful Randy Peterson can provide an answer about its accuracy.

I too have noticed that United earns a far larger-than-average number of postings on this site. I think the real reason has to do with a promotion that United had with Inside Flyer a few years back. The promotion undoubtedly boosted the percentage of Mileage Plus members among Inside Flyer subscribers, and had a few other interesting consequences, too.

The promotion was this: In the summer of 1992, United arranged for Inside Flyer subscribers to receive a free upgrade to Premiere status in the Mileage Plus program. The status was in effect for the balance of the year, regardless of how many miles subscribers had flown with the airline previously or whether they were even MP members to begin with. The offer was through a coupon inserted into every issue of the magazine. I was a regular United flyer already, but only logged 10 or 15K annually (Premiere level normally requires 25K miles/annually; Premiere Exec is 50K). I sent the coupon in and started to receive Premiere flight bonuses and upgrade coupons in Sept 1992.

I don't recall the specifics of what we needed to do to maintain Premiere status (my recollection is that we had to fly 10K by the end of the year), but I requalified for Premiere status for 1993. But I only flew about 18K on United in 1993, and I assumed my status level would descend back to the lowly depths of regular members. Wrong. In Nov 1993, I was boosted to Premiere Exec status, without explanation (not that I complained). In 1994, I flew "only" 36K with United and yet my Premiere Exec status remained in effect for 1995! From then on, my status level in the program was based on the same rules that apply to everyone else.

Why did United do this? Back in 1992, Inside Flyer's annual Freddie awards were swept by Continental's OnePass, as they had been since the beginning of the awards, as I recall. I think that United calculated that by boosting a few thousand Inside Flyer subscribers to Premiere level it might earn them enough favor among voters to buy the award. It didn't in 1992. But my boost to Premiere Exec level occurred in Nov 1993, just as ballots for the 1993 awards went out. United did win for that year, and the following. It was sometime after that that the voting was opened up to non-subscribers, and United started to fare less favorably in the voting.

Now, there were probably other factors at stake (one of which was that Continental's program fell out of favor for awhile), but I believe the primary reason United could advertise "the best" frequent flyer program in the industry for several years running is that they gave the relatively small number of voters exactly what they craved most: more miles. What better payoff could we ask for?

Subsequently, I think a large number of Inside Flyer's long-time subscribers are Mileage Plus members.