Do I Haaaave Toooooooooo?

Sam is a talented kid.  Math and reading come easy for him.  Because of that, I try to encourage him to read.  We have a "rule" in our house that you read for 15 minutes a day.  Of course, no one follows this rule (like most rules at this point, unfortunately.)  With Sam, even though he whines and complains and says it's too hard, I don't believe him because I have read with him. Maybe it's just that he's done with Magic Treehouse.  So one day, he was going through the recycling and said, "Oh, mom! I'm scared to go into the woods."  "Why, Sam?" "Because there are bad people there."  "Why do you say that?" And then he pointed to the following:

I was so frustrated--you'll read advertisements in random public service announcements, but you won't read a book?  Sam's first grade teacher, who worked with him a little last year, was on to him.  She figured out that he loved non-fiction and got him a National Geographic reader for kids called Deadliest Animals. He loved it.  We've found similar things--a beginners atlas, more scary snakes, etc. and finally he sits down and reads without being asked.