If I read and enjoy 'The Replacement' by Brenna Yovanoff - which involves changelings - I might then decide to look into 'The Iron King' by Julie Kagawa. The writing style will be different, which will allow me some variety, while still keeping to young adult literature and continuing my reading on faeries.
If I read the Temperance Brennan novels by Kathy Reichs, I may be interested in novels by Jonathan Kellerman or John Grisham, as all three authors write in the crime/thriller/suspense genre and have professional experience in the field that they write about.
If I read a Stephen King novel, I would probably want to read more Stephen King because I'm not sure I could get away with comparing it to anything else.
I personally like to think of myself as an eclectic reader, glad to explore many different genres. There are a few genres which I simply do not like, due to personal preference, but I try not to limit myself too much. Even so, I have to admit that it is easy to fall into a comfort zone, and when you do it is much harder to delve into something unfamiliar.
Some readers stick to what they like, unwilling to stray far from their chosen genre. Often, the only way I have found to encourage someone to read a book that they might not otherwise consider was to read them an excerpt. It's somewhat of a pushy tactic, but it's been proven to work. If the hook and the writing are good enough, it catches their interest.
I don't know that I've been a very eclectic reader lately. I have books of many different genres sitting on my shelf, but right now I find myself so often "not in the mood" to read certain books that I view as "difficult" whether because of their size, theme, or the fact that I have fallen into my own little comfort zone elsewhere.
How about you? Are you an eclectic reader or do you tend to stick to one particular genre? What are the factors which encourage you to read a different genre or a new author's work?
All readers have their preferences, and reading is wonderful no matter what they are. I just think that once in a while it's a good idea to read outside the box. You never know what treasures you might uncover.