The key to everything

 You know that you need to focus on the benefit your product offers to your customers, not on all the features that you think make it cool. You know what does and doesn't make your brand. You know the importance of high-quality, trustworthy content.

Now you're ready for the component that lets you shape these ideas into something that actually works to make you money.
You need to test your marketing communication.
All of it. All the time.
If you're the chief marketing officer for Coke, you don't test every marketing dollar you spend. (I'm also slightly concerned that you're signing up for newsletters offering marketing advice to tiny businesses. Please give me your job immediately.)  The well-known saw is, "I know that I'm wasting half of my advertising money . . . I just don't know which half."
(It's usually far more than half that goes to waste, by the way.)
You might wonder why huge corporations would pour so much money into something they can't measure. This is what's known as an elephant in the living room. Actually, this is a great blue whale in the living room. Brand marketing departments create a lot of cool, cute, clever stuff. They want to continue creating cool, cute, clever stuff.
And as long as the results aren't measured, no one will ever find out whether cool, cute, or clever are the right way to go.
I think of this as the equivalent of a million dollar diamond necklace. If you have the money lying around and diamonds make you that happy, fine. It's your million dollars.
Unfortunately, it's not just giant rich companies that fall prey to this strategy. If you're a funky little company (or nonprofit, or organization, or project) with limits on the money you can spend, you might want to consider a different tactic.
If money matters to you, you want to spend every marketing penny on "direct response marketing" or what I like to call measurable marketing.
What's measurable marketing?
"Direct response" is often a code for "junk mail." But it goes far beyond that. The fact is, smart companies don't carpet-bomb our mailboxes with garbage.
Measurable marketing means:

· You select your audience carefully, finding the kind of folks who will be most likely to benefit from, and pay for, the product you offer.

· You send them messages--by email, snail mail, AdSense, print advertising, whatever--that focus on them very directly (that's the direct part).

· Then you ask them for a response (there's your response). 

You then follow up on that response in a systematic way, and you measure like crazy everything that's going on.
This is not necessarily high-tech or hard. A flyer tacked up in the supermarket with those pull-off phone number tabs can be measurable marketing--just be sure you put in some kind of code so you'll know which location is getting the best results. (For example, the flyer that says "Ask for Sam" is in Safeway and the one that says "Ask for Ken" is in Kroger's.)
Simple, well-targeted mailings of plain letters and postcards (cheap to print, cheap to send) can work extremely well for businesses of any size, as long as you put a lot of thought into who you're mailing to.
And those ugly little text-only ads in the back of magazines--the really cheap ones--are a much smarter investment than a gorgeous, cleverly-worded full-color ad that you'll pay a fortune to have an agency develop and another fortune to run.
What makes measurable marketing work?
Three things.
You've got to ask for that response. Ask for it explicitly—remember. Don't be subtle about this; customers will not, in fact, "use their common sense" to get in touch with you. Ask.
You've got to measure and measure and measure. You need to capture and track where every response is coming from.
(You can do this in slightly sneaky ways, like creating a second Web domain for a campaign and re-directing it to your main one, then measuring the traffic. This takes about four seconds and eight bucks if you use GoDaddy, with another two minutes to set up Google Analytics on your main site.) You also need to track how many total dollars you've spent getting that response.
Ideally, you'll also track how well those different lead sources turn into customers, then into really, really good customers. You may find that you get a much higher-quality customer from ads in Magazine A than you do from Magazine B, but you won't know that if you don't track and test.
This tracking is the hard part. It's not too difficult to set up a simple spreadsheet or notebook if you're small, but it takes discipline to maintain.
It gets harder to set up and easier to use as you grow--there are software programs out there designed to do this task very well, and once you set it up you won't have to hassle much with it.
A lot of folks let tracking intimidate them. Try to keep the big picture in mind. Tracking can be kind of hard, especially at first. Working all the damned time for no money is really hard, and it never gets easier.
Finally, you've got to keep experimenting. Don't assume you know what's going to work. A lot of us discard "cheesy" advertising ideas.

 So try some cheesy stuff and see how it works. Once in awhile, try something everyone says won't work ("overestimating" your customer, long paragraphs, short copy, whatever) and see what happens.
In particular, keep tweaking headlines, then measure how they do. It's not uncommon for changing a single word in a headline to result in a 10x better response.
anything you can think of. Tweak until you're getting fantastic results for very moderate money. Then create a new product and start all over again. As you go, invest in better systems to keep making things easier for yourself, so you can scale your business without turning into (or remaining) a workaholic.
Repeat until you're just tired of making all that money.