It's becoming clear that all of your Category Development work is dependent upon having a viable Merchandise Solar System.
In other words, you have a category that most customers prefer to purchase from. This is your "Star". Everything revolves around the Star.
You have planets. Planets revolve around the star, but planets have their own moons as well. For instance, in an apparel brand you might have Mens Casual ... that would be a planet that revolves around the Star (Womens Casual, for instance), but Mens would have moons as well (Mens Outerwear, Mens Footwear).
You have comets. Comets have unusual orbits and they come in-and-out at odd times. Think about certain Christmas gifts you might sell ... these items are irrelevant the entire year and then for six weeks they appear with a green tail, not to be seen again after December 20th(ish) ... until the following Christmas season.
Once you understand what your Solar System looks like, you make smarter decisions. Want to sell more Mens Outerwear? Sure, you can pay for keywords, or you can develop Mens Casual so that you have more "pre-qualified" customers who want to buy Mens Outerwear. The latter point is frequently missed among marketers. Use your categories appropriately and you can grow a moon-level category by growing a planet-level category, and the planet-level category can be grown by attracting customers to your "Star".