A hundred years ago a shop might have tried to be many things to most people. In fact, big box stores still do that today, with good success. Walmart is everything and all things to those looking for the cheapest price. But even they repel customers – namely those people who value service and quality over price. These days it pays to specialize. Rather than trying to be most things to most people, you want to do one thing and do it really, really well. If you teach gardening techniques, rather than teaching everything to every gardener, pick a focus such as organic vegetable gardening. If you teach marketing, teach it to a very specific audiences, such as chiropractors or coffee shops or contractors.
Yes, you'll be repelling the vast majority of customers, but you'll also be attracting the exact prospects you can help the most. And in so doing, you can also charge accordingly.
After all, who commands the highest price – the person who teaches generic marketing techniques to anyone and everyone? Or the specialist who teaches plumbers to build their businesses to seven figures? Every time, it will be the specialist. If you don't believe it, look at the health care industry, one of the biggest businesses of all. Who makes more – a general practitioner or a heart surgeon? Specializing pays, and it pays big.
One more benefit of specializing and perhaps the most important of all is this: You become the ONLY choice. When a dentist wants advice on building his practice and he's faced with 10 choices – 9 of whom do marketing for any kind of business and 1 who works exclusively with dentists, there simply is no competition. Even if your prices are double or triple of your so called competitors, because you are the specialist you will win the business nearly every time and almost without trying.
Bottom line: Know exactly who your target audience is, become their ONLY choice, and repel everyone else who is not a good fit. You'll attract better customers who appreciate you more and are happy to pay for your specialized service and products.