Stephen Foley: Shoppers aren't so keen on revealing what's in their baskets

US Outlook: Google knows where you've been on the internet. It probably directed you there.

The company scans your Gmail emails and tracks your website visits looking for clues that it can use to target ads specifically to you. If you have an Android phone, it has beenlogging your every physical movement, too. And it got into trouble for scooping up email addresses and home WiFi details when its Google Maps vans camephotographing your street.

Google is already the company that knew too much. Do you really want it to know where you're shopping and what you're buying, too?

This was the new frontier that Google opened up this week. With much ballyhoo, it unveiled an"e-wallet", an app that means, instead of having to reach for your bank card, you can pay at the check-out by waving your Android phone at an electronic reader.

For a variety of reasons, including the difficulty of getting partners on board and the fact there are many competing technologies out there already or coming soon, Google is going to have a hard time establishing this new product.

Everyone seems to want a piece of the mobile payments market: in the UK, former Marks & Spencer boss Sir Stuart Rose and Charles Dunstone, founder of Carphone Warehouse, are backing a new system; in the US, the major telecoms operators got together to form Isis to develop a different standard; unusual players such as the web browser company Opera want to anchor a mobile payments system for developing world phone companies. And we haven't even heard from Apple yet.

Google may be a juggernaut, but this is a small trial in New York and San Francisco of a technology that is currently available on only one make of Android phone.

Even given these impediments, you wouldn't necessarily bet against Google bashing enough retailer and banker heads together to make it work.

But what about the consumer? The main problem I foresee is public resistance to putting this much information, and therefore power, in Google's hands.

The company is not planning to charge customers for using thee-wallet, or to charge merchants an extra fee on top of what they already have to pay Mastercard for processing the transaction. Word is the company is subsidising the installation of the electronic readers for some of the early-adopter retail chains.

Instead, it hopes to find ways to profit from the new information it has about what we are up to.

It is working with major retailers so that they can merge their store cards and loyalty programmes into Google Wallet, and it is planning to take a cut from any special deals and promotions that it can lure you into taking up. Explicitly at the launch, the company said it would sync the wallet with its Google Offers service, its Groupon copycat, through which local merchants can advertise discounts and special offers that are targeted to you based on what Google knows about you.

I do trust Google to provide customers with proper opt-in and opt-out options for all these bombardments and intrusions. I also believe the company is motivated to fashion the smoothest, most customer-friendly solution, with the most room to add exciting new functions we haven't even dreamt of yet.

But as Facebook found out, when it introduced its ill-fatedBeacon technology, which broadcast details of what its users were buying on e-commerce websites, consumers have confounded the technologists before and proven remarkably resistant to the idea that their shopping habits should be tracked and exploited. Given a choice between Google Wallet and my own battered leather one, I'll stick with what I've got thanks.