My friend Chris recently spent the night at the Villisca Axe Murder House in Villisca, Iowa. In 1912, somebody bludgeoned to death the entire family of Josiah Moore and two overnight guests. Two adults (the mom and dad), their four kids and two neighbor kids. After the bludgeoning, there was some axing for good measure.
No one was ever convicted of the murders, despite some prime suspects. You can read all about the crime on the house’s official website.
Here is Part 1 of Chris’s account of his stay in the house with two of his bestest friends and his sister. The house is operated as a kind of tourist/hotel destination. The cost to stay in the Murder House is now $400 per night. So, yes, the owners are making quite a bit of money from the place and they do have a vested interest in people remaining interested and scared. That being said, people do feel and experience strange things in the house.