Try this, for the conservative investor.

Take $50K from your ING/Emigrant account.
Invest in Ameritrade, $50K = 25K AA miles.
Buy $50K of American Beacon Money Market Mileage Fund, approximate return = 2.62%. That almost makes up for the loss of interest from the ING/Emigrant account.

The MM fund earns you 1 mile a month for every $10 invested. That works out to 5,000 miles/month. 12 months = 60,000 miles.

That's 85,000 miles for keeping your $50K in a relatively liquid, safe investment.
Interest earned @ 2.62% = $1310, plus 85,000 miles.

Compare that to Emigrant, which gives you 3.5% on your $50K.
Interest earned @ 3.5% = $1750.


Granted, you could probably do better than the American Beacon Fund, but you wouldn't get the miles.