Who says there is no M&A any more? WPP made no fewer than 40 acquisitions, in 21 countries, in the first half of 2012. That is nearly two a week. Sir Martin Sorrell must have an awful lot of air miles. (Actually, due diligence in many cases is done by sector and country heads.) Can it continue? Yes – it probably needs to. WPP generated about 30 per cent of its ￡5bn of first-half revenue in fast-growing markets such as Asia-Pacific and Latin America, and the same from digital advertising. WPP wants those proportions to rise to 35 to 40 per cent.

Many of those acquisitions were of minority stakes, so investors should keep an eye on the bigger ones. WPP acquired majority stakes in 56 companies between 2009 and 2011, after the collapse of Lehman Brothers. The total amount spent was $870m; they are expected to contribute about $1bn of annual revenue in 2012. That looks like a reasonable acquisition strategy. But an eye-catching acquisition such as AKQA, which WPP bought for an enterprise value of $540m in June – more than twice the target’s expected 2012 annual revenue – would be harder to justify if it does not meet its target.

If WPP had not bought AKQA, which fits with its strategy of expanding its digital advertising, a rival – Interpublic, Publicis or Omnicom, say – would have done so. And investors appear convinced. WPP’s shares have offered a total return in the year to date of double that of the FTSE media index and four times the wider stock market. Its shares trade on a forward multiple of just less than 11 times earnings, a shade below Publicis.