Select Amex Cardholders: Spend $300 at Marriott Bonvoy, Get

Be careful on that one, as I think it only applies to "Homes & Villas by Marriott Bonvy" not their normal properties.

I'll say this - I've had an offer similar to this before, except it was only for Marriott properties (not Courtyard, Fairfield, etc). I went to a Marriott hotel, bought a physical GC (which took some effort as basically no one there knew how to process such a charge), then used it at a Residence Inn. The transaction (only for a physical GC) triggered the promo. It worked out for 2 reasons - I wanted to use the transaction for a hotel that wasn't explicitly mentioned as qualifying (but Marriott GC work for all Marriott hotels) AND I wanted to use it for after the promo expired (GC's don't expire).

I am thinking of doing the same for this promo , but as I said buying a GC in person was quite the anomaly last time. In fact, IIRC I had to go to 2 different Marriotts to do it - the first one said they didn't even sell GC.

When it comes to triggering the promo, these promos usually have all these T&C however I find that "no GC" is common yet is basically ignored; e.g. the Best Buy promos always say that but you can buy GC no problem. That said I would try to stick to the TC as much as possible. So for example:

"Qualifying purchase means a purchase at a participating Marriott Bonvoy® property made during the offer period"

AmEx does get a lot of info about purchases from merchants, but one thing is for certain is that all merchants have a merchant code, and they'll absolutely be able to tell if you purchased something online vs. @ B&M, so to give you the best chances of triggering the promo, I'd go B&M and buy the GC. That's no guarantee it will trigger though.

Had 20% up to $60 on my Amex Bonvoy. Last week I used the offer to purchase a $300 gift card from the front desk of a local Marriott resort and the cash back has already posted.