I think your intention to think long term is very smart. PPC is short lived and leaves very little traffic after the payments are gone. I would focus on a long term strategy that includes some serious social bookmarking as well as twitter campaings, facebook likes and google + likes. This will give you excellent visibility on search engines and you will get higher quality traffic which means better sales.
The latest research from Google underscores the importance of having a mobile-friendly website. As consumers continue to spend more time on mobile devices, mobile page load speeds are critical to a good user experience. Over 50% of mobile users abandoning sites that take longer than three seconds to load, but most web pages take a lot longer to load, creating a significant gap between consumers' expectations and most businesses' mobile capabilities.