What to make of today's news that Microsoft has tabled a $44.6 billion offer to buy Yahoo!, a move spoken of as imminent since at least May last year and rumoured since 2006?

Well, in terms of snap analysis, "wow" – the appraisal offered by TechCrunch, the well-read technology blog - does the job pretty well.

For while Microsoft may be immensely rich (with a cash pile of about $30 billion), the biggest deal in its three decades to date has been the $6 billion acquisition of aQuantive, the online advertising specialist it snapped up last summer.

Likewise, while everybody has known for years that Yahoo! – the Forrest Gump of the online ad sector - needs a serious fix, the thought of these two totemic technology companies forming a cohesive whole has somehow never really gelled.

As The Times noted in May, if "Yacrosoft" – the unlovely name used to refer to the combination – becomes a reality, the result, you have to suspect, will be an equally inelegant marriage, driven by necessity and not love.

If the deal happens the real broker behind the union of the world's biggest software group (Microsoft) and second-largest search engine (Yahoo!) would be Google.

In his letter to the Yahoo! board, Steve Ballmer, the Microsoft chief executive, admits as much. He says: "Today this market [online advertising technology] is increasingly dominated by one player [Google]. Together, Microsoft and Yahoo! can offer a competitive choice while better fulfilling the needs of customers and partners."

The bankers prodding Mr Ballmer to splash the cash will no doubt be pressing the line that the combined bulk of the Yahoo! flagship website and MSN, Microsoft's web division, will create – in terms of advertising inventory at least – a counter to Google's dominance.

The merged group would have roughly about 33 per cent of the search market – still lagging behind Google's 50 per cent. But it could surge ahead of Google in terms of the eyeballs attracted to its sites.

The trick, of course, is converting those visitors into cash – something that must primarily be done through advertising. Mr Balmer told The Times last autumn that Microsoft was having to face up to a world where consumers are increasingly used to getting stuff for free.

Here, Google has excelled– by building a superbly efficient and effective mesh of advertising technologies that "monetise" internet traffic – the most famous element being its search engine.

The thing is, Microsoft and Yahoo! have both known this for years and have been falling over themselves to create – or buy - their own advertising technologies that can compete with Google's. That's why Microsoft bought aQuantive and Yahoo! has spent furiously on the development of Panama, a rival new advertising platform. It's also part of the reason it's hard to see Microsoft and Yahoo! – with their rival proprietary technologies and bolt-on acquisitions - as complementary.

Doubts also abound on whether the two companies would gel in terms of culture.

When Yahoo! was created by Jerry Yang and David Filo in 1994, Microsoft was already 21 years old and the largest software developer in the world.

Indeed, eager to retain his young Turk credentials, Mr Yang, now the Yahoo! chief executive, is said actively to dislike Microsoft products, and to go out of his way to avoid using them.

His company's plummeting share price has left him little choice but to hear Mr Ballmer out. In May last year, Mr Yang could have spurned a $44 billion bid as derisory. Today it represents - at $31 a share - a 62-per cent premium on Yahoo's closing price last night.

Oh, to be a fly on the wall on the forthcoming Yacrosoft bid talks.

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