The WHY...
It's not quite as easy to attain, but the 'why' possesses much more potential return on investment (ROI).
Once you understand why some people buy your brand and why some don't, only then are you really able to make more meaningful change. Knowing that Brand 'A' improved share by 0.003% in the last year must mean something, but understanding why means a whole lot more.
Consider these following examples:
Home Furnishings
A home furnishing brand saw sales rocket because they rolled out a new display: So roll out more and more of the displays then! The true reason why sales increased was in part nothing more than the ways the room sets were photographed. So instead of investing heavily in expensive displays, all the brand really needed to do was change the style of their product photography: Much less expensive, but much more impactful to the bottom line.
Sweet Treats
Sweet treats were performing much better in one chain of Food To Go stores than another. Quick, copy everything the successful retailer is doing, right? The much less expensive solution was to understand why, which revealed that the location of sweet treats in relation to other food to go categories was the real reason why one chain outperformed another.
Salad Leaves
This is perhaps my favourite: Sales of fresh salad leaves in a particular August dropped significantly. And after much continuous sales data analysis and other in-depth research into just what was going on, the answer came back as... ...the reason why sales of salad dropped was... ...because it rained more in that August. No s**t Sherlock!
Summary
Retailers and brands are spending huge amounts on data and research that identifies what is happening, and what has happened historically. But real insights tend to come from understanding why. Take a look at your own research spend. How much are you potentially wasting, finding out the what? And how much should you be investing discovering why?
I've spent the last 30 years analysing shoppers and consumers for many leading brands and retailers. And in my experience, those who have benefited the most almost always did so because, between us, we got to 'Why'.