Is "marketing" really the reason your product isn't selling?

I recently had an interesting conversation with a very smart business professional who claimed the reason the products in her company weren't selling was that there was no "marketing." By "marketing," what she really meant was "advertising," a common misconception. So, I agreed with her immediately. It has to be the marketing. But, what aspect of the marketing plan is not working? Is it really the "promotion," "marketing communications," or "publicity"?

The longer you work in marketing, the more you realize that many people simply just know what marketing really is and does. I've had many executives ask me to "make things look pretty" or "generate awareness" for a product that is in the maturity stage of the product life cycle. In fact, there are also people who fall into marketing jobs and who learn about "marketing" from shows like Mad Men...

Marketing really is "the systematic planning, implementation and control of a mix of business activities intended to bring together buyers and sellers for the mutually advantageous exchange or transfer of products." (Source: http://marketing.about.com/cs/advertising/a/marketvsad.htm)

So, when my friend claimed that "marketing" was the problem, she was right. However, maybe not in the way she meant. Maybe the products of her company are not strategically placed? Perhaps the store is not in the right geographic location for the target market of the product? Or maybe the products are not that visible in the store? It's also possible that the sales professionals are not well-trained to sell that product. Or, it could also be that there simply is no need or desire for the product.

It's true that advertising is a crucial, useful, factor to the selling process. After all, no one will buy a product if they don't know it exists. Nevertheless, if business hire expert market researchers to evaluate the entire business as a whole and strategic marketers study industries, target audiences and buyer personas, they might find that advertising and promotion alone is not enough to sell a product and, therefore, simply cannot be the sole reason a product doesn't sell.