Complex sentence: It was released on April 15 2009, both as a normal CD and a limited edition CD + DVD package, both containing a card with a serial number on it, used in a draw, a promotional event for the single.
Split into simpler sentences: It was released on April 15 2009, both as a normal CD and a limited edition CD + DVD package. Both editions contained a card with a serial number on it used in a draw, as a promotional event for the single.