The biggest long-term threat to rewards credit cards is declining interchange fees, as the cost to process transactions falls each dollar pushed through a card’s network is less valuable and thus less worth incentivizing with miles or other rebates.
And indeed, Chase’s interchange fee income fell 2% in the first half of 2015 despite greater charge volume. But Chase has a deal with Visa that allows it to get aggressive hanging onto partners and bringing new ones on — and it’s highly-incentivized to do so.