It is a particularly broad definition. One could argue that 'anything in business can fall under marketing in some way'.
A personal definition I like to use is 'marketing is any activity designed to increase the top-line sales revenue number'. If you research and launch a new product, that's marketing. If you cold call, that's marketing. If you write inventory control software, that's not marketing. If the software reduces delivery time, that's marketing (since you could argue that improved delivery time translates to increased customer satisfaction, and ultimately increased sales).
A personal definition I like to use is 'marketing is any activity designed to increase the top-line sales revenue number'. If you research and launch a new product, that's marketing. If you cold call, that's marketing. If you write inventory control software, that's not marketing. If the software reduces delivery time, that's marketing (since you could argue that improved delivery time translates to increased customer satisfaction, and ultimately increased sales).