I live year round in hotels so do this regularly. The real "deals" do happen through the sales director. It depends on a lot. I am currently in an extended stay which wants people long term, and the sales director here has given me a rate I could not have found for any apartment this nice in this area (one bedroom, full kitchen, including a washer and dryer in unit). The place I stayed here (same city) last year had a sales director more keen to cater to traveling sports teams and group deals. I got a discount but she harped on and on about it. They lost thousands of dollars of my continued business because the woman could not bother to reply to emails. This happens too (and you want your quote in writing).

One key can be the long term stay. I am usually tax exempt because my stays are unbroken 28-32 days (depending on the state). But continuing business may make a difference. Again, it really depends on the director and flexibility of that person. My current guy is a really nice, easygoing all-around good guy. That woman who was whining about a $3 difference also whined about her commute and how hard room blocks were. You get the idea.

Other factors that play into good rates are the city/area of the hotel. If it's a bustling area that is virtually always filled with visitors, they need business less than if there are high/low seasons. (Chicago in the winter will get you a better rate; forget a great summer deal.) Likewise, the sales director works for a company which is not likely to be the hotel. E.g. The Hilton Garden Inn is not usually owned by Hilton. It could be Concord, Aimbridge, or a whole slew of other corporate hospitality entities. The group itself is likely telling hotel managers where that bottom line needs to be. Sales directors have targets and quotas.

I'd advise asking at the desk who the director is and then seeing is you can get a face-to-face. The FD person is usually able to adjust to the lowest rate they can see is widely availble to at least some guests. But the sales director can have different rates. The rate code in my current reservation literally says "Sales Director."

Of course, YMMV with all of this insight, as my experiences differ from hotel to hotel and I have been doing this for almost three years now. But maybe this helps a bit.

Good luck!