"Worried about layoffs and the economy broadly, people have not only balked at spending more for brand name products – they've outright refused. Yet manufacturers continued to raise prices, in part because of rising commodity costs and in part to keep shareholders happy," he said.
As a result, stores and supermarkets have been forced to eat at least some of the increase – shrinking the store's profit margins.
Enter private label.
It's true that years ago private label was synonymous with cheap food in black and white cans. At that time it screamed, 'I'm poor and can't afford brand names.'
But that was the 1970's.
"In recent years the perception of store brand has changed considerably. Shopping clubs such as Costco deserve part of the credit. Costco's house brand - Kirkland - is quite well respected," Cramer said.
But the trend goes well beyond 'respected.'
"Today there are a handful of store brands that have developed such loyal followings– shoppers seek them out instead of their national counter-parts. (Think Trader Joe's)."
And supermarkets have caught on. Many of them now try to out-do the national names not only in price -- but also packaging.
Conagra's acquisition squarely addresses the trend.
"In the consumer packaged goods business having a private label brand has become the most important way to grow your company," Cramer said. And as we said above, the massive acquisition will transform ConAgra into the top U.S. producer of store-branded foods.
However, there's a bigger takeaway.
"After the Great Recession we now live in a world where value-buying is considered a necessity for many -- and clever by everyone else. Consumers just won't pay more for the same exact product simply for well-known labels," concluded Cramer. "It's an irreversible pattern and one which Conagra CEO Gary Rodkin knew he had to leverage just to stay in the game."
Call Cramer: 1-800-743-CNBC
Questions for Cramer? email@example.com
Questions, comments, suggestions for the "Mad Money" website? firstname.lastname@example.org