I purchased one for my extensive travels across Eastern Montana as a Veteran Services Officer. While I still do not have 100% coverage, it is a lot better than before.
To put it into perspective, this is the size of the area that I get to cover all by myself. I'm not posting this as a "woe to me", but to illustrate how much better/safer my travels are with this booster versus not having one.
My "main" area is 27,225 square miles and this is 462 sq. miles smaller than the combined area of Vermont, New Hampshire and New Jersey, which is 27,687 sq. miles.
Since I am closer to Forsyth Montana, my Boss "bequeathed" that chunk of Northeast Rosebud County, so I conservatively estimated my coverage area at 2,275 sq. miles, and even if I was off by 500 sq. miles or so, it is still bigger or about the size of Rhode Island which is 1,545 sq. miles.
I can honestly say, and I do not feel that I am stretching the truth in saying, that I cover an area that is the size of 4 Eastern seaboard states. In my area, there are 12 Counties, and one partial one, that are bigger than the whole State of Rhode Island and I have 4 Counties that are larger than the State of Delaware. The 2 "small" Counties out here in the East is Wibaux and Daniels, and they are only 889 and 1426 (respectively) sq. miles in area.
The one thing that correlates between cell coverage and no coverage is the population base. According to the population estimates in 2011 Rhode Island had 1,051,302 people and the whole State of Montana only had 998,199, but there was a lot of news stories this year that Montana went over the 1,000,000 mark. Thankfully, most of the population is out West, or centered in the Bakken Oil Patch.
Needless to say, there is a lot of open area out here on the Prairie and the population base of animals far exceeds the human population. With that being said, the coverage gets sparse and it is easy to find areas where cell phones do not work. I still find area's that I drop calls or miss calls, but thankfully they are few and far between.
Cheers,
Oly