Originally Posted by
cbn42
I don't think Chase could go on its own. It's not just about market share, but reach. If Chase wants to be a viable card network, they will need a broad range of merchants to sign up, at least as many as Discover. They will also need to get other merchant services banks on board, because it's obviously not feasible to require that every merchant have an account with them. Other merchant services banks are probably not going to want to support their competition.
They'd also likely need to partner with (or actually build out) networks in other countries to ensure that their travel focused cards are somewhat usable overseas. AmEx already has a reputation of being uncommonly accepted outside the US and they've been in the card network business for a pretty long time; a new network with even lower acceptance probably won't do so well.
Thinking domestically, though, I don't see stores signing onto a fifth credit card network unless there's something in it for them (significantly lower interchange and/or more pro-merchant chargeback policies).