I bit on the Ameritrade offer for Starpoints. Wasn't really worth it. For one thing, it was a little tricky getting a decent rate for the invested funds. Their default rate is lousy. And, there is a $50 fee when you close the account. And, while I had the money at AT, they changed the commission on fund purchases and sales from $20 to $50 so it would now be quite costly to go in and out.
It is nice to get bonus miles. ^ But, maybe putting $25K into bonus miles is overkill?