Share Of Wallet - SOW

Consumers only have so much to spend, especially when they go to the grocery store. Their wallet has a limited amount of cash in it notionally (includes credit cards and debit...but there exists a perceived "budget" above which consumers just don't wanna spend).

So if, say, Joe Consumer spends $126 each week at the grocery store, and Procter and Gamble wins $42 of that weekly spend via the 87 products they have on the shelves, then PG's share of wallet is 42/126, and they'll seek to up that number.

The notion is that the spend is more or less fixed, in that grocery store expenditures aren't really going up; they're just a zero sum game with the big players trading around market shares, which then lead to profitability and happy shareholders. So they fight for that share and the extra earnings per share in their stock price.