NEW YORK (MainStreet) — AT&T, T-Mobile and Verizon have bet many millions of dollars that you will want to do your shopping with Isis - a mobile phone based wallet - but here is the puzzler: Isis went live nationally last week and, so far, reaction among consumers and merchants adds up to a big yawn.

Does anyone care?

The draw is that with an Isis phone, you can pay at participating merchants - which includes any merchant presently capable of accepting contactless payments - and that means many McDonalds, Jamba Juice, Circle K, CVS, and a number of other national retailers. No need to swipe plastic to pay. Just use your phone and how cool is that?

Fact: some 24 million smartphones in the U.S. are Isis capable, said Jim Stapleton, chief sales officer at Isis. That basically means the phones are equipped with Near Field Communication (NFC) - a tap and pay technology - and that they run on Verizon, AT&T, and T-Mobile.

iPhone owners need not apply. Ditto for Sprint customers.

Isis shrugs off those absent players. "Every month two million smartphones are added to the total," said Stapleton - meaning that pretty much all new smartphones on the participating carriers ship with NFC.

Have a new phone, and it's easy enough to start on Isis. Download the app - at Google Play - and off you go.

Have a phone with even a little age on it, however, and even if it has NFC, you probably need to visit a store of your carrier to get a special SIM popped in.

If your phone doesn't qualify for Isis - around 40 models do, said Jamie Johnson, head of marketing at Isis - you are looking at buying a new phone, perhaps with no carrier subsidy. That could mean shelling out $500 or more.

And then what?

There's the rub.

Asked how many consumers had downloaded the Isis app, Stapleton declined to offer even a rough count.

By the count at Google Play, there have been 50,000 to 100,000 downloads of the Isis app for Verizon Wireless, a like number for T-Mobile, and only 10,000 to 50,000 for AT&T. Big those numbers may sound, but for the national launch of a purportedly cutting-edge payments platform?

The iPhone 5, by contrast, logged an estimated 2 million pre-orders in the first 24 hours it was available. Some experts peg opening weekend sales for the new iPad Air at over 5 million.

The Isis numbers look anemic by contrast.

"How many consumers even know about Isis," shrugged Greg Smith, an analyst at brokerage firm Sterne Agee.

He added: "It's tough to find optimism about Isis."

The other side of the pessimism is that - a handful of national retailers aside - to get significant acceptance of Isis at mid-sized and local retailers would require stores to upgrade to new terminals. That may happen as they face a 2015 deadline for accepting so called chip and PIN cards, aka EMV, or face penalties from Mastercard and Visa.

But most smaller merchants seem to have shrugged off the threats. That means contactless payment likely will not be widely accepted until perhaps 2017 at the earliest, suggest many experts.

Oh, a third rub: right now only American Express and Chase are supporting Isis. You need an account with one or the other to be in the game. Capital One and Barclays had participated in Isis pilots, but they since dropped out.

This is sounding ever less compelling?

The upshot: there really are not that many places to use an Isis phone to pay, not that many phones are Isis-capable (especially when the entire iPhone universe is excluded), and not that many financial products sit inside Isis.

Is Isis DOA? Andy O'Dell, a co-founder of Clutch, a mobile wallet competitor, predicted: "Isis will eke out a part to play in this universe, but it will not have a dominant position."

What that means is: It is safe to sit out Isis. If you have an Isis ready phone, sure, give it a try. If you don't, don't sweat it. When and if you upgrade in the normal course of events to an Isis ready phone on a carrier that supports it, sure, why not instal Isis and at least dabble in paying on the run with a mobile phone?

Until then: know you aren't missing out on much.

--Written by Robert McGarvey for MainStreet