The aerial view of a town shown in the first clip of the opening titles montage is not a town in Ohio, or even the United States. It is part of a town in the United Kingdom. Tell-tale signs include the style of houses and gardens, the street lighting, the European car models and - most conclusively - the British-style road markings, including a bus stop and a "driving on the left side of the road"-style "give way" junction marking.
The black crow and the name of the town is a direct reference to the demon and 7th spirit of The Lesser Key of Solomon , Aamon
There is a "Wicked" poster in the girl's bedroom and they watch the movie "Vertigo". Both are stories with related themes to "Devil in Ohio".
Of the 68 cast members, 27 have appeared in Supernatural. From young "Dean" to the angel "Gadreel" to "Demon #3".
In the hallway by the bedrooms, there are three height charts with the numbers 666 in a row at the top.