I did for 6 months at a homewood suites (4 nights a week for 6 months). I worked with the hotel GM and had a competing offer (the Hilton down the street) and the name of my client (as a consultant my company didn't have any type of volume there, but the client did). I did have to sign a long term agreement, but I was at about 60% of rack rate.

It took some work ahead of time, but I ended up extending a few extra weeks, and ultimately they were not very happy about that, as they had planned the discount rate out only so far and now I was pushing it further.

Remember, there needs to be something in it for the hotel. Losing a room for 6-7 months at 50% of the rack rate can, and usually is, a negative to the hotel if they do any kind of normal volume. They want more business at rack rate from your business partners more than they want you for long term at a significant discount.