Now 'thingy' could be David Beckham advertising whisky, George Clooney flogging coffee pods or Robert De Niro shifting packs of bagels, but what they all have in common is being more memorable for who's in them as opposed to what's being sold in them.
Let's not forget, the whole point of advertising is getting your product remembered so that one day, somebody might consider buying it.
Getting a celebrity to appear in your advertising is relatively easy (as opposed to coming up with a great idea which is ridiculously difficult), as long as you have the budget to match your ambition.
It's amazing what already wealthy people will do for a few more quid in their pension fund.
You're banking on the fact potential customers will link said person and the name/benefits of your product. But all too often, this simply doesn't happen. Whisky Beckham will look all mean and moody in his ads, coffee Clooney all suave and sophisticated, and bagel De Niro will play the characters he's well known for.
And for a bucket load of your brand's cash, you end up with the people in your ads getting remembered instead of the brand itself. Pretty crap deal if you ask me.
Some advertising bloke called David Ogilvy agrees with us too.
Here he is chatting on the David Letterman show about why he regrets using celebs in his client's work.