Many Marketers focus on Incentives first. Incentives are important. Friction reduction has far more impact though. And improving Traction is more sustainable.
Incentives are Campaigns, Promotions and the like.
Traction represents your brand awareness, product quality and word of mouth reputation.
Friction is what makes it hard for people to buy your product or engage with you.
Improving Traction has a lasting impact, and is typically a better use of resources than investing in Incentives (think great content marketing vs. buying PPC clicks).
Reducing Friction has for more impact then improving Incentives or Building Traction.
Fricton reduction should be the priority that trumps everything else.