Many people use Facebook as a marketing tool and rightly so. It's a great way to connect with like-minded people over a new product, book, or idea. This morning I had the unpleasant experience of someone bombing my author page with SPAM to go to his page and like it. "You've been tagged, come like my ___ page."
Curious, I went to the page and was accosted by ridiculous innuendo and posts that were blatant in their "Look at me, I'm an idiot" category. With a satisfied sigh, I deleted his post on my page.
Possibly 10 minutes later, I get another post on my page. "Liked. Would you consider liking my author page too?" Score one, polite. Score two, win-win....you liked my page, I'll go peek at yours. You're an author, score three...something in common thus content I can relate to.
Visiting (and liking) other people's pages who are in a similar business can be a win-win for you both. You can learn from each other to discover marketing strategies and techniques, discover new products (we do what we do because we love it), and increase the potential to gain a guest on your soon-to-be new friend's blog, or a possible collaboration in the future for a cross promotion.
Reach out, but don't dive bomb.