This is the first in a series of excerpts from ROTOMA—The ROI of Social Media 'Top of Mind,' a brand-new book I just co-authored with Spencer X. Smith. The book is now available at Amazon.     The excerpt:   Unselfish Selfies. I continue to learn a lot about how to work the levers of social media simply by watching the master at work. Spencer’s the man when it comes to all this stuff, and…