Originally <a href='https://www.sportsbookreview.com/forum/showthread.php?p=28771835'>posted</a> on 07/19/2019:
They do it so they have a chance to move the number, if they choose to.
The books who actually move on action instead of air, which are very few anymore, usually allow re-bets after a sufficient amount of time to evaluate their position on the game and decide if a line move is necessary.
Nowadays, there are very few bookmakers left who actually take a bet, move on action, and take a re-bet.
Most are just clone-joints who just copy lines, don't know how to book, and kick out anyone who wins.
They do it so they have a chance to move the number, if they choose to.
The books who actually move on action instead of air, which are very few anymore, usually allow re-bets after a sufficient amount of time to evaluate their position on the game and decide if a line move is necessary.
Nowadays, there are very few bookmakers left who actually take a bet, move on action, and take a re-bet.
Most are just clone-joints who just copy lines, don't know how to book, and kick out anyone who wins.