Northwest and US Bank are offering 20,000 mile enrollment bonuses with no fee the first year for the Visa Signature and Business card products.
US Bank cards have had mixed results with churning at best, most customers will only be able to earn the bonus once for each card type (at least based on my rather dated understanding of the issue). But it’s a good deal for folks who haven’t had either card before.
It’s worth noting that if the Northwest-Delta merger closes, there’s a pretty good likelihood that the US Bank relationship with the airline will eventually end. That’s quite a ways off, and doesn’t really effect the decision to take this card now, but worth noting. The American Express relationship with Delta is a stronger one, and represents a better card in any case for actual long-term use.