Sitting in an AC in Miami killing a five hour window before departure and out of boredom decided to browse flyertalk ;=)

ok, I've only casually read through all these pages, but here's my question. Since I see virtually no mention of credit card miles can I assume that a Platinum Challenge can only be satisfied with actaul miles flown on a trip?

Also, is the advice to wait unti after June to issue a challenge because of the length of time a platinum status will be enjoyed if the challenge is satisfied?

Thanks!

bradesp