When do people use sunbeds?

I love Google Trends for things like this graph, where the numbers carve out a picture of people's otherwise unknown behaviour, like hitting the sunbeds in the first few months of the year. This makes perfect sense but would have otherwise remained a secret had I not decided, on a whim, to search for "tanning bed" (not that I was looking for one or anything, even though now would be the time to search for one!)

I suppose this sort of information could be factored into AdSense to make things more seasonally relevant.