Maybe not huge but the three that I've encountered threw off between $12,000 and $20,000/year. To me, that's enough to make a substantial difference.
ON one of them, the owner surveyed off the tower area and kept it for himself; sold the dwelling and the remaining land. He moved away and still the tower was paying him good $$, $1,500/month.
Same goes for billboards. Some small boards on the edge of a farm 20 miles out of town might pay only $200/month. Other, large monopoles near the metro area along the freeway pay MUCH more $$, 1,000's /month.