Expensive, gratuitous M&A eventually came to exemplify the indulgent decline of Yahoo in recent years. The $1.1bn acquisition of picture website Tumblr in 2013 has just been written down to less than $400m. It is a lesson Yahoo’s acquirer, Verizon, would be wise to acknowledge.

Yesterday, the US telecoms titan confirmed it would acquire Yahoo’s internet search and email businesses for $4.83bn. Yahoo will be combined with AOL, that other 1990s internet dynamo that Verizon bought last year for $4.4bn. The telco wants to create a solid third digital advertising option for marketers, after Google and Facebook, one that can energise a company whose mobile and landline phone businesses have stagnated (their revenues fell by nearly 2 per cent in the last quarter).

Whatever bet Verizon is making, it is not a massive one. Its market value is a juicy $230bn, while the combined value of the AOL and Yahoo acquisitions is less than $10bn ( Facebook and Google, against whom AOL/Yahoo will line up, have a combined market cap of a whopping $850bn). There is a certain sense of humiliation for Yahoo. Having once claimed it was a winner in the mobile internet age, Yahoo had to sell itself quickly under siege from activist investors. Its growth rate, once merely mediocre, turned truly dreadful last quarter, dipping nearly a fifth.