The key point about the cobra effect is that when you set a naïve target, it encourages behaviour that superficially meets that target, rather than the underlying goal.
The targets set on most digital activity measure short-term effects: immediate sales, visits, views. These short-term approaches are popular as they’re easy to measure. However, ease and appropriateness are different things. After all, we know that the majority of advertising’s effect is long-term.