Absolutely agree, SEO has become extremely tough. One thing we focused on since last year is create visualizations of interesting datasets. But the amount of effort is atleast three times the effort required to produce an article. First we are always on the lookout of interesting data that can be used for visualizations and then see what kind of interesting charts and insights are generated, next do some research around the topic and complement the charts. We then post to various galleries. Twitter is great for getting engagements when you share visualizations.
Recently we have been following the advice "Fix the leaky bucket" given in the Traction book. It is a slow and iterative process. I think this should be the number one priority for any startup. I can see now that lot of the efforts we did before we started fixing the leaky bucket are kind of waste of money/time and resources.