SEO definitely isn't dead, but it most certainly has changed.

Where are you spending your ad money?

Are you promoting your most popular items that likely already sell themselves?

Or are you spending ad money trying to help out a struggling product?

My recommendation?

In my most basic of marketing classes at university we explored the 'what is marketing' conversation.

Like most intro classes, the answer was broad and short.

Marketing is delivering a product that solves a customer's problem.