Normalisation
Actually, frank, they claim they used census stats to get back to a sensible average.
Yes: I agree that the map suggests something weird is going on in Upminster...and its probably data weirdness, rather than an actual aspect of the average Upminsterian's sexuality...but I'd still like to know.
As someone who has done serious data analysis in the past, I would love to get my paws on this data and do some sort of geodemographic overlay. Yes...such analysis will throw up all manner of epiphenomena - such as the finding I made many years back of an association between reading Playboy and being an HSBC customer! - but might also reveal some interesting social stuff.
As for the status of this data...it is what it is. Its not really research: its just the data from the lovehoney accounting system matched to a couple of geo bases (including population counts) and overlaid with a slightly greasy text generator.
It'll be quirky, as I bet they haven't taken the trouble to clean the data and examine outliers properly...but so long as you don't apply too much weight to it, its all just a bit of fun.