Here's a trick question for you.  What was probably the most read, almost certainly the top bestseller in the English language, of 1847?  To help you out, these books were published that year: Wuthering Heights, Jane Eyre, Vanity Fair, and poetry by Alfred Lord Tennyson.

That's right, the top bestseller of 1847 was Varney The Vampire.

The full title is  Varney The Vampire, or The Feast of Blood.  It's freely downloadable from several sites if you want a look.

If I'd included non-English books, Varney would have had a close run with The Man in the Iron Mask plus two other books by Alexandre Dumas.  Dumas was not only a busy lad himself, but he kept a small factory of authors to churn out books published under his name.  Which when you look at how some thrillers are produced these days, shows that publishing really hasn't changed.

Notice that gives us paranormal, plus action/adventure/thriller.  Genre rules, and has done since time immemorial.

Varney weighs in at a mere 667,000 words.  Imagine trying to get a publisher to read that these days.  But then, Varney appeared originally as a serial, so it's probably more accurate to compare it with any modern day  series, at which point it becomes standard length.  It's shorter than the entire Harry Potter series, for example.

Varney was the first vampire story to hit the big time (Bram Stoker was born that year).  It was the first story to give vampires fangs that leave two puncture wounds.

It's also almost as badly written as Twilight.  Anyone who can read it from end to end is probably insane (I mean Varney, not Twilight), but it does have some good scenes (Varney again, not Twilight).  I particularly liked the bit where Varney challenges an adversary to a duel with scythes in a dark room.  I must work out how to steal that.

There's nothing new under the sun, nor under a dark night sky for that matter.