Turds and tiaras
Good copywriting has more influence on conversions than design, but as the saying goes, you can't polish a turd...
At the same time, you'd be hard-pressed (no pun intended) to trick someone into a tiara being poop.
Good copy is situational and subjective.
You can have the best offer described in the best way. With the wrong timing, it's not the tiara you think it is.
Understanding what customers care about at which stage of the buying cycle helps you create copy that fits them like a sparkling tiara.