Advice wanted: split loyalty?
 

I know the usual rule is to concentrate one's flights on one airline to maximize benefits. Generally, I agree. Is this an exception?

I switched from Delta to American in mid-98 and am Delta Gold Medallion for 1999 based on early 1998 flights. As long as I am at least Silver Medallion I can use 200,000+ previous program miles for awards under Delta's more generous previous program Medallion award schedule. Otherwise, I have to claim award certificates by the end of this year (fly any time during 2000) or use the miles under the current award schedule.

Situation: I'll requalify for AA Platinum AAdvantage with my next flight. I have zero chance of making Executive Platinum because I usually fly discount coach so I'd need nearly 200,000 flight miles. However, if I switch to Delta after my next flight I have a good shot at 25,000 DL miles before the end of 1999. That would keep my Medallion string going one more year. It would also extend the life of my DL miles for another year, but that's a minor consideration because I'd probably fly with them again anyhow before the miles expire in August 2001.

The question: other than four 500-mile AA upgrade credits for every additional 10,000 miles with them, what - if anything - would I give up? Assume AA and DL miles are equally valuable. (I have comparable elite status on both airlines, so both will give me double mileage for all flights.)

The combined wisdom of FlyerTalkers exceeds that of any other known group of humans. I appreciate all comments and suggestions.

Depends how you fly and how you upgrade.

American may have better upgradeability on more fares? but Delta has less points required to get an upgrade (only 10K)--are select fares same as American's any fare?

I go with the airline that gives me the most perqs (ie. easy upgradeability) and then the one that gives me the most miles. Everyone has to decide for themselves on this one. You said that you would likely use the Delta miles by 2001 anyway.

I would go ahead and get your Delta rewards now and continue to fly AA (more partners, oneworld etc.), if you like their service and if they can regularly upgrade you and if getting reward travel is relatively easy.

Perhaps something wasn't clear in my previous post. I wouldn't necessarily use all the miles by August 2001, but I'd have at least one more Delta flight so they wouldn't expire. This makes the expiration-extension value of flying Delta this year trivial. (As opposed to some other programs, Delta miles don't expire unless you have zero DL flight miles for 36 months.)

To respond to BlondeBomber's question: Delta "select fares" exclude deep-discount "L" fares. In my limited experience, upgradeable Delta fares cost more than the cheapest AA fare PLUS the cost of AA 500-mile upgrade "stickers," especially at the elite bulk rate of 8 for $200.(There's more on this topic, including not a little frustration, in the Delta forums.) That was one reason, though not the only one, for my switch.

Good point, though. I'd probably spend more time in front in AA than in DL.