I do this all the time to get stay credit when there are low rates at cheap hyatts. I make the reservation, go to the front desk and check-in and leave. On occasions, I have even told them I do not plan on using the room, so if they can check me out in 15 minutes - it will free the room up if they need it - since in theory the should have offered me the best room.

Ditto and likewise. I've "stayed" several nights at a nearby HP, to max out nights for promotions. Admittedly, I have not done this in 2017 (because they haven't had any promotions worth maximizing), but I did it as recently as Spring 2016.

• Call or visit hotel's sales department
• Explain that an avid Hyatt customer lives nearby and needs to earn nights for a promotion
• Ask them to find me a really low rate which qualifies for stay credit
• Ask them which upcoming night they prefer me to book, to help out their monthly charts and graphs and such.
• Book their specified night at the given rate.
• Show up on the appointed day.
• Tell front desk that I'm checking in and out, strictly to earn stay credit, and that I won't even be visiting the room.
• The front desk performs the transaction, and never even offers a room key.
• Credit card gets charged for the night, Hyatt account gets stay credit.
• No doors were harmed, or opened, during the making of this stay credit.

To the best of my knowledge, Hyatt requires you to show up in person, in order to get stay credit. Even if you check-in on the app, you must still show up in person if you want points.

Yes, you can get points/stays if you show up. Sounds like OP wasn't able to show up as he/she left on earlier flight.

While this is a Hyatt thread, I say be careful about doing that at a SPG property. I did this on a recent stay where I used 1 room but booked 2 others. When I checked, my account a couple of days later, I only had 1 room credit. I called customer service and they said that it was due to me checking in and out the same day. I actually didn't request to be automatically checked out but that's what he did. I just mentioned that I was only using the rooms for stay credit and to give me any room they wanted. They gave me the credit though.