Who won Christmas? Well, we’re not entirely sure yet. But that hasn’t stopped pundits giving an answer. When it comes to online shopping, analysts are increasingly turning to social media to track customer sentiment.

Between 14 and 24 December, research firm SpectrumInsight looked at “highly positive and negative emotional content, including happiness, anger, disgust and contempt of real-time tweets covering online deliveries and click & collect services”.

Its findings scored retailers by the number of positive comments they generated versus negative (rather like goal difference). It gave positive marks to Ocado and Sainsbury’s, while Tesco, Asda, Waitrose and M&S fared less well in its index. Examples of complaints included Waitrose and John Lewis customers fuming over late Christmas deliveries; and M&S consumers who reported “chaos” over orders made just before Christmas. By contrast, Ocado was praised for meeting tight deadlines and making few substitutions.

But just how accurate can such data be? According to SpectrumInsight’s director, Mark Westaby “the error of the findings is plus/minus 2.5% at a confidence level of 95%”. The results take into account neutral comments, and the data makes use of a statistical technique called “bootstrapping”, which Westaby says is “extremely robust and just as, if not more, reliable than statistical methods used in most traditional research”.

The problem with such Twitter-based research, of course, is that it can only rely on the customers who bothered to pick up their smartphone to vent about poor service (or, less likely, those who took to social media to praise good service).

Westaby says that for those consumers who can’t be seen – ie. those who don’t feel the need to tell the world they have an Ocado delivery – “these are effectively the same as consumers who are not included in a traditional market research sample”.

Whether or not you buy into it, it’s clear that social media monitoring has become another yardstick by which to measure retailers – or just a stick to beat them with. But as for who won Christmas – only cold, hard sales figures will give that answer, and we’ll have those soon enough.