Honestly, my view is that demand reduction [1] is a monoculture that has taken over conservation and produced very little positive results. In fact, it could be argued that demand reduction has even increased wildlife consumption via boomerang effects [2]! I would like to see another school of thought, harm reduction [3], challenge the demand reduction orthodoxy.

TL;DR: I can think of no campaign that can reduce demand; although, I can think of several that might accidently increase it.

[1] https://en.wikipedia.org/wiki/Demand_reduction

[2] https://en.wikipedia.org/wiki/Boomerang_effect_(psychology)

[3] https://en.wikipedia.org/wiki/Harm_reduction