It's a fact of life in the fast-paced world of marketing that there's never enough time to plan and execute your next campaign. Even with the best intentions and forethought, campaigns more often than not fall victim to competitive pressures, sales goals, product lifecycles, and other business drivers that inevitably mean one thing: the campaign needs to launch more quickly than planned.

Under these circumstances, testing can seem like a luxury: one more level of complexity for which no-one has the time nor the inclination. One subject line? One list? One ad? Hey - it's all we had time for!

Give me a break. Testing is not only vital; it's easy. If you're doing most of your marketing online, testing adds very little complexity and at worst, nominal cost. Plus if you don't test, you increase your risk of failure substantially (more test cells means a greater chance of at least something working). You also lose the opportunity to switch horses midstream (proverbially speaking) if one message, list, audience or other variable is performing substantially better.

Furthermore, assumptions about the best message, audience, or media vehicle for your campaign are just that - assumptions - and even the most fervently held beliefs about your market are only as good as the amount of time and effort you've expended in validating them with field tests.

Testing doesn't have to mean two completely different creative platforms (those tests rarely teach us anything; the variables are too many to know why one succeeded and the other failed). But here are three simple tests you should do more often (but aren't):

1. Message.

Change one word in your subject line or banner ad or text link and do a 50/50 split. You can test key benefits (swap "increase speed" for "decrease cost") or just semantics (whether or not to use "Free" in a subject line is a legitimate test, even today).

2. Audience.

How sure are you that C-level contacts really care about your product? That IT will respond when it's really Finance that lies awake at night worrying about the issue? The right audience is the first step to a successful campaign. Don't put all your eggs in one basket.

3. Offer.

Offer a free book to the first 50 responders. Give away an iPod at the Webinar. Add a free trial to "qualified companies". Just remember to test it. If you change your offer across the board, and response increases, you'll never know for certain whether your change had anything to do with it.