Don't get me wrong - you have to have a kick-ass product or service. It's a given in my book because if that's not the case and your stuff can't 100% genuinely help someone and add a ton of value - you shouldn't be out there in the first place. Target a specific niche or market when your marketing message can get a response.
To the point where you feel confident enough where you can almost feel like you're guaranteed to get a response. Think of it like this: Don't fish in the entire ocean using generic bait. Fish for mackerel in the area of the ocean where mackerel email list hang out and use mackerel bait they want. You should think about your marketing in the same way.
Identify and define the peeps in your niche, find where they are and where they hang out, and then develop the marketing that will get you the response from them that you want. One last word of advice: Never delegate marketing. It's like the rule of never delegate the checkbook in your business. You can delegate certain aspects of your marketing (like the technology, implementation, etc.) but never, ever delegate your marketing efforts. It's the lifeline of your business. How do you not only make your customers happy, but keep them coming back for more?