i gotten those letters too. a couple times I got $50 or $75 vouchers.

I think the $75s were for broken parts delays..

i just remembered while typing this up of a time when we swapped planes (plane was at gate x6), FA got on the horn and said, "everyone off, up the jetway and across the terminal, our new plane is at gate x7". Amazing how many people couldn't walk straight across the terminal without wandering around. Took another 20 minutes to round everyone who had wandered off...