But these triumphs were fleeting. There was no such thing as the perfect e-mail; every breakthrough had a shelf life. "Eventually the novelty wore off, and we had to go back and retest," Showalter said.
In my experience in the content game, nothing has proven more true. Any detailed social media primer I give you would be out of date by the time I could finish writing it. Any operational headline writing strategy would stop working if everyone used it. Everyone clamoring for your attention on the web is trying to strike that perfect mix of familiarity and novelty. And that means the content techniques that work are necessarily recursive. You change what people like by doing whatever you do. Which then requires that you do something else, which then changes their tastes again.
This is true for your core donors (or readers) as well as the farther flung people who might only get forwarded your fundraising email (or story) every once in a while. Sometimes, I start to think of the Internet as a gatheration of starlings, each reader/writer moving in response to her immediate content environment, and somehow the whole thing seems to move together, following a million different versions of the same core set of rules.