When you conjure images of your local Home Depot (NYSE:HD) or Lowe's (NYSE:LOW) in your mind, there's a good chance you're envisioning contractors with dusty boots pushing carts full of drywall or plywood. Or men with their sons, merrily examining power tools. But take a closer look and you'll see a lot of women there, too.

The big home-improvement retailers are increasingly focusing on female consumers, and with good reason. For example:

  • The home-improvement market is huge, estimated at a quarter of a trillion dollars, with roughly a quarter of that (more than $50 billion) being purchases made by women.

  • Lowe's has estimated that roughly half its customers are women, while Home Depot says that about 55% of its non-contractor customers have no Y chromosome. The private ACE Hardware company, which operates smaller stores, puts its figure at 42%, but notes that women tend to spend 30% to 40% more per visit than male customers do.

  • Lowe's has found that about two-thirds of its female customers own power drills, while a Home Depot survey found that half of women polled want to learn to use a power tool. (It also found that 68% of the women would rather work on home improvements than shop.)

Of those women who are not doing actual home-improvement work themselves, many remain very influential. A Lowe's study found that women initiate 80% of all home-improvement projects.

Therefore, it should come as no surprise that hardware retailers big and small are courting women -- with features such as brighter lighting, wider aisles, instructional workshops, and more.

Other companies are getting involved, too. For example, the private Barbara K company is marketing tools specifically designed to appeal to women, while the Tomboy Tools company is selling "not-pink" tools for women through a Tupperware-like distributor system. Newell Rubbermaid (NYSE:NWL) has also gotten in the act, with its line of "Tough Tools."

So next time you're evaluating a home-improvement company as a possible investment, examine how it's addressing female consumers, as that's a major key to its ultimate success.

You might do the same for other industries, too, as women wield a lot of influence all over the place. Ford (NYSE:F) and General Motors (NYSE:GM), for example, are likely aware of this. According to the WomanMotorist.com website, "Women now influence about 85% of all new vehicle purchases.. 52.2% of all new vehicle purchases are made by women."

Longtime Fool contributor Selena Maranjian doesn't own shares of any companies mentioned in this article. But she does own a cordless drill and a level.