We need to remember that we're not motivating kids to do a distasteful thing. A good meal can be very motivating in and of itself. When we do this, we are establishing the idea that reading is something you have to be bribed or coerced into doing. It sends the message that what you are actually being asked to do is not worthwhile or pleasing. Reading should be treated like a beautiful banquet, motivating in and of itself.
Nothing can be more motivating in our lives than a good role model.
When children see the people who are significant to them happily involved in a book, they get a message. Reading is fun and absorbing, a great way to spend your time. It's a little like missionary work. You can talk about missionary work all you want in your family, but when an older brother or grandma and grandpa go on a mission, talk becomes meaningful. Someone your child loves and trusts is making that choice, and the message comes home.