Two “Secrets of My Success” from LinkedIn founder Reid Hoffman in the latest issue of Fortune Magazine apply to sales & marketing professionals as much as they do founders & CEOs:

Be Willing to Change Course
Entrepreneurs tend to believe, “I’ve got my idea, I’ll go until I die.” But I advise them to take seriously the questions about whether their plan is irredeemably flawed and whether they need to change what they’re doing. Be diligent about failing fast so that you don’t spend five years doing something that’s just going to fail.
(the lesson for marketers: measure what’s working, evaluate impact on sales & revenue, and quickly make adjustments or move on if it’s not working.)

Don’t Be a Perfectionist
I frequently tell Internet entrepreneurs, “If you’re not somewhat embarrassed by your 1.0 product launch, then you’ve released too late.” There’s value in launching early, getting engaged with customers, and learning from them. That can direct your progress.
(the lesson for marketers: stop talking about it, and just do it! Don’t be afraid to make some mistakes, and spend the majority of your time executing.)