Mo Cheex is onto something. I have recently switched money between various brokerage houses. Took money from Fidelity to another (for me temporary) investment then brought it back to Fidelity to accrue mileage for "new" money to an existing Fidelity account.

Now with the Ameritrade offer, I took some of my Fidelity investment and transferred it "in-kind" (not selling the investment itself, just having it an Ameritrade account). I need to leave it there for NINE months (not six!) in order to obtain the full 25,000 miles. After those nine months I will transfer the investment back to Fidelity "in kind." No tax consequences, money is invested in the same mutual fund with Ameritrade as it was with Fidelity.

Altogether for investing no new money I will have made something like 50,000 miles.