The position during a bidding round is so important that the strength of your hand depends on it. Thus, some hands that deserve a revival at the end of the lyrics are not even playable at the beginning of speech.
The advantage that gives you a good position is primarily informative. If you talk, you have information on the play of opponents. You know how many players have entered the event and how many have reopened. You can get a clear idea of the coasts of the pot before making your decision. When you talk first, you do not know the number of players who will be present, or whether the pot will be revived. Thus, hands too weak to follow a revival, as the connectors 9 and 10, should be avoided in early position.
Another advantage to speak is that you urge your opponent slow players and thus give you free cards. Imagine that you have Ace and 2 of hearts. You are at the button and everyone went to bed. You decide to revive the Big Blind and you call. The flop is: K 8 3 with two hearts. The big blind player to check, thinking that you will revive because you’ve done preflop. But you check and see a free turn, which is a 4 of hearts and offers color max. Your opponent bet, you restart and he announced carpet. You pay, it shows KK, a very strong hand because its kind was the main maximum on the flop. You therefore get his carpet easily.