We’ve always recommended that you book Marriott hotels directly on the Marriott website because their rates match the online travel agents. And booking direct has other advantages:

• The hotel will have the guest name immediately
• Additional flexibility if there’s a problem as you’ll be able to deal direct with the hotel rather than via an intermediary
• More tailored booking options such as specific room types etc

But now there’s an additional reason;

Marriott is offering free WI-FI but only to Rewards members to who book directly on the Marriott website, its mobile app, via a call center or through a particular property. –

Travel Management Companies have complained to Marriott as this policy means that their bookings will not include the free WI-FI

For now however, we continue to recommend booking direct at the official Marriott website