You know when you buy that new coat, the one that looks great in the shop, and then you take it home and realise it's a god-awful piece of knitwear destined for a lifetime at the bottom of your cupboard.
Imagine that times a million. When football clubs spend big-money on a shiny new centre-forward they expect/hope for a return on their investment.
Not necessarily financial, but certainly in terms of goals and performances. Often it will work out just fine, witness Luis Suarez at Liverpool or Sergio Aguero at Manchester City.
But sometimes it doesn't go so swimmingly. Just today, West Ham co-owner David Sullivan admitted he would not have spent £15m if he realised just how injury prone the England international is.
Ah, painful regret. So what about other similarly awful signings that, with the benefit of hindsight, should really never have been sanctioned.
What's the criteria here? Well, they have to have been pricey - preferably close to a club record fee - and they have to have flopped.
That may not have been through any fault of their own - it could have been injury trouble or incompatibility with the coaching staff.
Click through the slideshow to see the top five…