It's targeted, so the code won't work for you AAARGH.
I am Select Plus and did not get the offer. Wonder what the target list criteria is for the triple miles?
It's based in part upon your lack of riding Amtrak. The typical seems to be someone whose gone 2-1/2 to 3 months without taking a ride on Amtrak. Additionally it seems, although there is no way to prove it, that some consideration is given to your normal riding patterns.
In other words, if you typically take only 2 or 3 Amtrak trips a year with long gaps in between each trip, you are not likely to get an offer. On the other hand if you typically ride at least once or twice a month and then go 3 months without a ride, you are more likely to get an offer.