If you fly 3 qualifying round-trip flights: you get Silver Elite until February 2005. If you fly 6 qualifying round-trip flights: you get Gold Elite until February 2005.
Only flights on Continental and Continental Express (not on partners like Northwest, Delta, Alaska, etc.) qualify, and then only on mid and high fares (not Q, S, T and L fares).
They made this offer earlier this summer, and though it was targeted it seemed to work for everyone — at least anyone who called could get upgraded to silver instantly. Since I’m not signing up for this myself, I don’t yet know whether folks who didn’t receive the offer will be able to take advantage of it or not.
Bear in mind that most complimentary elite status offers are good only once — so sign up only if you plan to use it.