I've been a Global Services member for the past two years (not sure I'll get it again this year) and I can't tell you exactly what the qualifications are (although they did come out last September and state in letters to current members that flying 50,000 miles in full fare coach, business or first was one certain way to qualify). Most of the speculation around other ways to qualify had to do with overall revenue and/or revenue per mile.
The two years I have qualified, I flew 250,000 miles one year and 175,000 miles the next year, but did have a substantial number (5 or 6 -- can't remember) of business class international flights which I'm sure went a long way towards getting me qualified. Unfortunately, last year, while I did fly 160,000 miles, none of it was in business class (other than upgrades, of course) -- hence my concerns about getting it again this year.
So, what does this secretive level get you?
- Top of the list for upgrades and they clear 120 hours prior to departure (1K members clear at 100 hours). With this status I was able to upgrade 68 of my 70 flights last year.
- Automatic re-booking with highest priority if there's a schedule change or cancellation - usually before I'm off the airplane. I've even had them re-route me when it looked like there would be delays on a connection through Chicago -- without my asking for it.
- Early boarding with 1st Class (in case you aren't in first class). They are even starting to do some Global Services only boarding prior to first class at some airports. One might ask why someone who flies that much would want to get on early -- it's all about storage, especially if you're in a bulkhead seat. I hate having to swim upstream to get my bag, or even worse, having to check it.
- Use of the United Arrivals facility in select international airports, even if you aren't booked in business or first class. Being able to take a shower when you arrive after an overnight flight is a great thing.
- In one particular airport, London Heathrow, they really try to treat Global Services as special -- they meet them at arriving flights and drive them to the connections center -- saving a long walk through the labyrinths of Heathrow. This is the only airport that seems to have a dedicated team for taking care of Global Services people.
- Some have reported that Global Services members get gratis upgrades all the time. I haven't found that to be the case. In the past two years, I've gotten a gratis upgrade probably 2 or 3 times.
I believe that this is because gratis upgrades are only given out when there's an otherwise empty seat that nobody's willing to pay for or upgrade into (and if you've flown recently, you know that there aren't all that many empty seats). In addition, I think that the paid fare has a lot to do with it as well. If you're flying on a full fair ticket for the class that you are currently in, you're probably first in line for the gratis upgrade.
For me, since I've been upgraded already (which I paid for in miles or certs), I think I'm at the bottom of the list for a "double bump" (upgrade of an upgraded seat). I even worked quite hard on my 23 hour leg from LHR to HKG via Chicago to get the double bump (mentioning that I went over 1 million lifetime miles during that leg, begging and otherwise making a fool of myself) to no avail (not that I'm really complaining as I was in upgraded business class the whole way).
Me, I'm hoping that they think my 160,000 miles, my going over 1,000,000 lifetime flight miles last year plus the fact that I'm already a member will get me at least one more year of Global Services status. I do like the benefits.