All marketing channels work if you work them.
Each appeals to different types of sellers.
Below are some channels that I have successfully closed at least one deal from:
โข Bandit signs
โข Direct mail
โข PPC
โข PPL
โข SEO
โข Cold calling
โข SMS blast
I have NOT closed any deals from any of the following:
โข Agent referral
โข Listed on MLS
โข FSBO
โข Facebook ads
That doesn't mean that they don't work, surely someone has had success with them; just not me. #KanyeShrug