I have to believe that most of the allure of setting up shop on 1710 is attracting a different crowd of listeners, in addition to "all three of us". 1710 is relatively open and clear here, and I suspect it is in many parts of the country. The PA/MA/NJ TIS stations on 1710 are only heard in the Midwest using serious equipment and never on the car radio or portable AM radio. With enough signal on 1710, I think it could really "get out" during the winter months. Driving home from a soccer game last night, I dialed up to 1710 and found this one playing oldies again. No specialized DX equipment needed. Of course, how many people these days are tuning around the AM dial in their car looking for different or new content? Probably not many. Instead of three, maybe an op can expect to double that number to six
Yes, 1710 is probably fairly open in the Midwest, and much of the country. For now, anyway. I have to expect that since the FCC has been granting licenses for 1710 in the northeast, this will continue and expand. Here in the Northeast, 1720 would be the place to go. Of course there may be the "no stations on 1720 so no listeners on 1720 so no stations on 1720..." problem. Which I think also applies to west coast SW pirates and listeners.
I don't know, but it's always a rush catching a pirate on MW, especially on the car radio while driving down the highway!
Indeed! For several years, there was a semi local MW pirate on 1610 that came on between Thanksgiving and New Years, playing Christmas music. "The Wedge". I could hear it here at home fairly well, and even on the car radio. It was fun to listen to. Sadly I've not heard it for some time.
The only other MW "pirate" I recall hearing is one from Baltimore that was actually from a school. "The Claw" ?? I think they had a misunderstanding regarding Part 15 / Carrier current regulations

Only heard them for a few weeks IIRC, I think they got a clarification from the FCC.
The local college in Westminster, McDaniel, used to have a carrier current operation on 1620 that I could hear up here (10 or so miles away) that might also have been somewhat generous with FCC regs. I have not heard it in a few years, I am not sure if it is even on the air anymore. Back in the 1980s when I went to U of MD, there was a carrier current station, and it was tough to even pick it up in the dorms on campus. Next time I am in town I will give 1620 a listen and see if it is still on the air.