I'm not a local, and I get the same mailed offer as kiwiboy1, but usually a little less in freeplay. I also get mailed offers for free tournaments and concerts, both of which usually include additional free nights. I always work through my host at M, even when taking marketing offers. This way I'm able to get additional nights and some additional food comps. I go there from 4 to 6 times a year.
M has been my main hotel/casino in Vegas for some time. I realize that things are always changing in Vegas, and that you never know when or why a given property might fall in or out of love with you. If you think you're giving a place decent play but you're not getting what you want from them, it's probably best to look elsewhere.