Used when faced with a difficult challenge. Came from the common instance when a school yard bully would take lunch money from a smaller kid and use it to by his own lunch.
In business, when a competitor is interested in your product and service, but goes to another company, they are "eating your lunch." This happens often when a company strategy or branding is weak — the prospect is interested in what you sell, perhaps because of your marketing...hits your website... but they are not engaged. Their reaction is lukewarm, or "I don't get it." They don't know why they should pursue their interest in your product or service. So they go elsewhere. And your competition eats your lunch. (What's for dinner?!)
In business, when a competitor is interested in your product and service, but goes to another company, they are "eating your lunch." This happens often when a company strategy or branding is weak — the interested prospect hits your website, but they are not engaged. Their reaction is lukewarm, or "I don't get it." They don't know why they should pursue their interest in your product or service. So they go elsewhere. And your competition eats your lunch. (What's for dinner?!)