To maximize your points, when making a reservation for multiple nights, try making separate reservations for 1 night each. For each reservation you get the choice of the bonus points or amenity.
For a 3 night stay booked as 3 separate 1 night stays, you can get 1500 bonus points (for platinum) instead of 500.
It does require checking out/in and getting your keys updated, but usually the hotel can keep you in the same room the whole time so you shouldnt have to pack up and move.
I like the idea of getting more points, but I had an experience similar to what you described. I booked two seperate reservations so I could get a cheaper weekend rate for pleasure and a Monday-Weds night stay at the gov't rate for business. I was told at check in that both reservations would be combined into one. I was told I could get the platinum welcome points once per stay, which, I believe, is defined as consecutive nights in the same hotel. Sometimes your idea might work...sometimes it might not I suppose. One advantage to what happened to me was that I did not have to move from the upgraded suite during my entire stay. If you check in and check out, you risking having to change rooms as you pointed out.
I guess it depends on the hotel. I made 2 reservations for my stay in DC last week (1 for the first night, 1 for the next 3) and got the platinum gift for each reservation. They originally didnt have me in the same room, but I requested it at check-in and they were able to accommodate. I know this has been my experience in the past as well.
I am going to try this again next week - I have 2 consecutive nights at a courtyard and I changed my single reservation to 2 separate ones. I will report back on how it goes.
Based upon my understanding of the Membership Benefits, the Guaranteed Platinum Arrival Gift of 500 points at a full service brands and 200 points at limited service brands is an elite benefit. 'Benefit' is the keyword.
That said, the practice of making separate reservations at the same hotel for stays involving consecutive nights for the sole purpose of obtaining an additional arrival points is questionable. In the context of article 12 of the Terms and Conditions, the practice might qualify as abuse.
The risk of having points forfeited or in the worst case scenario, having an MR account closed because of repeated abuse merits very serious consideration.
Ouch, that's pretty serious. I never thought it would be a violation of policy since the few times I have had multiple reservations like this it has never been an issue or even a question. Like Nuhusker, if the Sunday rate is cheaper than the monday-thursday, I will book it separately. This past week my travel plans changed and rather than modify my reservation I just booked a separate one for the additional night. In fact in DC I asked specifically when I checked in and mentioned my 2nd reservation if I would get the amenity/bonus again and the answer was "absolutely". The next morning when I had to check out/in to the same room and get my keys updated there was no question about offering the platinum gift. (of course you did see my post regarding the great service in DC so was this an anomoly?)
It also hasnt been an issue when booking multiple rooms at the same time - they have given the bonus points for each room.
I certainly would not want to violate Marriott's policies here, but if these are the conditions then they are not obvious based on my experience.
One way to do this "legally" (I'm not implying that it's illegal to begin with), is to book 3 consecutive nights in 3 different hotels. As inconvenient as that might be to some, in areas like DC where there's a Marriott every mile, I've done it before when a certain promo required so many "stays" to qualify, and it didn't bother me at all. But I realize that's not for everybody, just us hardcore points hounds.
At best you stand to gain a thousand points for playing your 3-night game. At worst the MR program provides that you can be expelled and your points forfeited. (I don't believe that Marriott would expell an elite customer over a thousand points.) Personally, I would pay a thousand points out of my bank not to go through the hassle of BS that you find appealing. Thanks for the tip ... but no thanks.