40 years ago this week the UK saw TV adverts for Strawberry Switchblade's Since Yesterday. TV ads for music were very unusual at the time, especially for a single.
Since Yesterday had been in the low end of the charts since late October. As the band garnered more attention, the record label thought that, with a bit of a push, the single could get through Xmas and be a proper hit in the new year. And they were right.