If you’re doing search marketing, including SEO and SEM, for your site(s) then you need to understand multivariate testing, the science of choosing various page elements, ad copy, keywords and other variables and testing them against a control. Your control is basically a combination of these elements that so far is your steadiest performing combination.
Jonathan Mendez is far deeper into this testing than I am and has begun a series of posts that go into how multivariate testing works into detail. This is complex stuff, but if you take the time to start learning and applying it to your search campaign, the payoff can be huge and the knowledge you gain will be a major business asset.
The days of pretending that there is some kind of separation between ‘branding’ and measurable direct marketing are over- everything is measurable and the results don’t lie. Traditional agencies and marketers take note: The creative director who ignores this reality in favor of amorphous ‘creativity’ is going to lose you clients.
If you’re a business owner this eliminates the old “I know half of my advertising budget works, I just don’t know which half (sorry, can’t find the attribution- if you know it please comment)”. With sophisticated testing, analytics and conversion tracking you can know exactly what dollars/creative are working and which are not.