I am curious as to what specific problem you are solving for women over 40? What other characteristics do these women have? Your marketing tactics will depend on your strategy and a key step in developing the strategy is to have a clear audience profile(s). Knowing your audience will help you to understand the best place to reach them - it may be online, offline or a combination of methods. If your salon is local, partnering with complimentary businesses who serve your market is one way to reach your audience. This could be a joint offer, event or advertising.