First of all, what you "require" and what you get might differ from what you want to see since all answers here are given freely on a volunteer basis.
My answer is you are comparing apples and oranges. Many of your potential visitors will access Social Media platforms, as well as search engines, through their phones. So if you want to see an optimal number of visits to your site, you will need to do both unless you can linearize the content of your site so it will fit in mobile devices without express development for mobile.
Whether or not you develop for mobile, you should still develop a Social Media presence that is targeted for your demographic.