Continual Improvement
Marketing is only as good as its results. That’s why I strongly encourage both state-of-the-art analytics, and continuous improvement.
Every action you take in marketing has a cost associated with it — and hopefully an associated reward. You must treat your marketing dollars very judiciously, and seek to continually get the best possible return for those dollars.
This is true for every aspect of marketing, but for purposes of this discussion, let’s focus on acquiring customers through advertising. When you start implementing a scientific approach to a given portion of a campaign, there will be a certain cost per customer acquisition. Over time, that cost per customer will trend downward, and at some point, reach an optimal point beyond which you have to spend more — not just in terms of absolute dollars, but in terms of dollars per customer. At that point, your results from that particular form of advertising are optimized — or, as I like to say, the medium is saturated.
Once that happens, you may still want to spend additional marketing dollars on that particular medium, as it may still be cheaper than going to the next most expensive medium. For example, with paid-search advertising, you may optimize at $10 per customer. The next cheapest form of advertising may be placed Internet ads, and those may have a starting cost per customer of $15. Even though your marketing dollars may not be ideally spent on the former, you’ll want to hold off on heavily investing in the latter until your costs intersect. Over time, that way, you’re continually using your marketing budget to it’s maximum effect, and continually improving your results, at each step of the process.