What is share of wallet?

Share of wallet is the percentage of an existing customer’s total spending in a category that goes to you rather than to competitors. If a customer spends $1,000 a month on marketing tools and $200 of it with you, your share of wallet is 20%.

It reframes growth around deepening rather than acquiring: expanding share of wallet through cross-sell and upsell is usually cheaper than winning new customers, and it squeezes competitors out of accounts you already hold.