My best deal is going on now- Etrade will give you 25000 miles on United if you open an account with a deposit of $50000 and leave it open for six months.

You don't have to buy stocks if you don't want to- just leaving the money in their money market fund gets you the miles just the same.

The rate is competitive with banks, and although not insured money market accounts are usually conservatively managed.

My bank, on the other hand, has never offered me miles at all.

So, for just changing the location of my deposit, I get 25k miles. Not bad!