The big ad firms and newspapers will try to tell you that the companies who perform best during a recession are the one's who continue to spend on marketing and advertising.

The problem with the argument is that, although ad spend and profits correlate well, it's not possible to know whether the continued marketing contributed to the success.

It might as easily be the case that the companies who failed during the recession would have failed quicker if they'd spent their money on adverts. Or the surviving companies would have had even bigger profits if they hadn't advertised.

Correlation != Causation.