My colleague, Sonya Sorich, recently wrote about her journey into "Fifty Shades of Grey," an erotic novel that's made it to #1 on the New York Times bestseller list.

Romance novels and erotica -- particularly those mass market paperbacks you find at the drugstore -- tend to get a bad rap. People point to their contrived plots, bad writing and the cheesy-looking covers.

But not all romance and erotica is bad. Here's what's in a good romance or erotic novel, according to a reader quote on Vulture.com:

“A hero who’s neither twisted and sadistic nor overly perfect. A heroine who’s not too stupid. No smuggling or kidnapping subplots. No gratuitous S&M or tantric sex. And no anachronistic names—women were not named Brittany in Regency London.”

In other words, a story and characters that are somewhat believable -- even in a paranormal ghost romance (yes, this exists).

I haven't read "Fifty Shades." I read through the first couple pages on Amazon.com and decided it wasn't really my thing. According to this helpful romance/erotica flowchart, I lean more toward Regency romances. No surprise really, considering my penchant for Downton Abbey.