I looked at one of the many marketing letters I get on its swift and painless journey to my waste paper bin, and I noticed that it had a PS.
PS is short for "post scriptum" (I have the Latin). It works like this. You write a long and interesting letter, sign it at the bottom, and then realise that there's something important you forgot to say. So you put "PS" and add this at the bottom, rather that rewrite the entire letter with the information included. Back in the days when letters were written by hand (with a fountain pen, remember those?) this made a lot of sense.
It makes no sense when you're using a computer.
It makes even less sense when we're talking about a carefully designed and thought out marketing letter. What, you realised at the last minute that you'd forgotten to say something?
So why a PS?
It's because the marleting people think you're more likely to read that.
I resent this - I'm being played for a punter. So - new rule - anything that has a PS at the bottom got straight into the waste paper bin. Or if it's an email (and yes, I've seen emails with a PS), into the bit bucket.