Be prepared to test your assumptions on a regular basis. If you came from traditional media, you know there’s a fair amount of unlearning going on right now because consumers are redefining how they consume media. For example, many people now use TV like radio. They’re surfing the Net with the TV on in the background. So visual payoffs on a TV spot miss the mark. In Internet marketing, things that were true once upon a time aren’t true anymore, and vice versa. People used to prefer and be more responsive to text newsletters over html. Now, for the most part, the opposite it true. The point is, nothing is written in concrete anymore. Yes, certain human behaviors and habits will remain the same. People will always operate out of their own self interest. But usage patterns, popular sites, and ad themes are no longer a forever thing. Remember the Pointcast network? Remember how hot Friendster was? Email frequency, SEO tactics, mobile marketing and the rest will never settle into “forever mode”. The tumultuous media landscape is the new constant. Might as well get used to it, and plan to revisit assertions that were once considered indisputable.