American readers will have been delighted by last night's announcement ('last night' is relative, it was last night in the UK) that Microsoft is going to offer cash back on items bought through its partners from its search engine scheme. The idea completes a notion that began over a decade ago with affiliate marketing; Microsoft affiliates to a load of sites, it gets a kickback every time someone buys something and in the US at least it'll start splitting the difference with its customers.

The idea on the surface is to get people searching with Microsoft rather than Google. The other possibility is that with economies over the world stalling, getting people back online with their credit cards appears to be in everyone's interests. There are equivalents in the UK; is a silly name with none of Microsoft's marketing clout but it's using the same idea without the search element.

The loser will be the newbie or naive end user who thinks that any of these search engine owners were ever interested in getting them the best deal on something. Microsoft is looking for market share and nothing else. Froggybank considers the idea of getting half of loads of commission better than getting 100 per cent of a little.

As long as people bear this in mind when they shop that's fine. They'll probably find bargains and maybe better bargains than before. There has never been a time when it's more important, though, to apply a sanity check to everything you find from a search engine - there's an increasingly good chance its placing has been paid for rather than earned by merit.