For this week's theme, 'stamps with a message', I've gone for a postal history angle, whilst the stamps themselves don't have a message as such, the message is in the slogan postmark.
Here are some I scanned . . . (click the image to see the larger version)
The slogan on the left (below) 'advertises' the 1971 census (for overseas readers, the UK population census takes place every 10 years, in years ending with a 1)
The top slogan (below) is one from Ireland, the next one is part of the countryside code, I remember seeing tv adverts along the same lines in the 1970s.
Below the FDC for the Robert Burns 1966 commemoratives has a slogan cancellation - 'Help save your Doctor's time' - I'm not sure what you were supposed to do (or not do) to achieve this, maybe not go to the doctor at all.
Finally a couple of seasonal slogans of which there have been many, I don't think they'd be too happy if you posted cards in bundles nowadays. We do still get slogan postmarks today, but they aren't as good as they used to be, not so varied and generally not so clearly stamped.
I'm participating in Viridan's Sunday Stamps, visit this week's entries by clicking the icon below.
Thanks for visiting.