We’ve received official confirmation from U2’s publicity staff on the procedure being used for the GA lineups:
“There are 2 lines: one for U2.com, one for the others. The U2.com line will be allowed in first, tickets scanned, and random selection will determine if the ticket holder gets into the ellipse or not.
Fan club members will be allowed the first entrance into the arena.
Once the fan club line has been exhausted, the other GA line will go through the same process.”
Now you know.