The strategy to provide a bonus to those who buy top products, consisting in devices made from the same manufacturing companies (Samsung in this case) is not new in the field, and now for Samsung Galaxy S4, such promotion is valid for each preorder at Galaxy S4 you will receive a free Galaxy Tab 2, if you pay now for the phone. I think it's a tidy affair and you, as a buyer, had just won: get quicker your desired phone, plus an exciting bonus. Moreover, you will get the phone with a few days before it is available at local retailers in the U.S.
In conclusion, if you sign a preorder now, you have only advantages: you get your hands on a high-performance mobile long before all others, and, following this blog, you'll learn how to get and bonuses of these preorders.