I'm a new silver, still struggling to understand the benefits.

I can in theory be upgraded? So I have to buy the thing that costs money and miles, and says it puts me on a waitlist, is that correct?

I'm Los Angeles <> EWR. But SNA is actually more convenient for me, which might help here. If I buy eco and place myself on the upgrade waitlist ... Are the chances better flying out of SNA vs. LAX? When would I generally know whether I had been upgraded?

tia, zc

Hmmm, I'm clearly not understanding, because this way of doing it charges me a bunch of miles -- so it is not a complimentary upgrade. Am I paying the miles to just increase the chances? They seem deducted immediately, so would they be refunded if I don't get an upgrade?