I have to say SEO is still the most used Online Marketing Tool so far. Of course nowadays it's hard work, but it's the best way to get a sustainable amount of users over a long period of time on your webpage/shop etc. For example in my firm it works until today in a way that no one of our sales reps has to make cold calls, since we get all the organic lead traffic we need.

But have to say, that I'm in the same mood as @spiritumax . I want it to be dead to me.