How to develop social media strategies to strengthen the marketing of your company?

It all comes down to the scale of the company and how big of an influence the company has over the community. The crux of any social media strategy is to reach the target audience, since here the quantity over quality debate might kick in.

Safe game in all cases would be to start off with closer network and then expand beyond. Regular PR, community service, and competitive advantage shared on social media is just a dot on a canvas. What is interesting though is coming up with what your competition has never thought and let them know they are competing with someone serious. Refer to Blue Ocean Strategy and try aligning the framework to social media. It does wonders.