Friday Thoughts: How do you pick books to review?

I'm a lazy person so I don't do work unless there's something that I get out of it. Blogging is a lot of work but I know myself and the second I decide the work is too much I'll quit. That's why I'm selective on which books I'll review. I don't see the point in reviewing a book I won't care for. Reviews come to me based on mood. Sometimes I'll write 4 reviews for books in a row, sometimes I'll read 5 or 6 books without writing a review. It all depends. 

So from this huge pile of books, how do I pick which ones to review and which ones to read if I'm not just counting on my mood?

1. Challenges. Books for challenges are likely to be read and reviewed. Like I read a lot of books by debut authors for The Debut Author Challenge. I review many of these books too because this is a huge challenge that is fun to participate in. It's a great way to get started on new and interesting series so since these books are in need of exposure to create a fanbase, I'll review them. Challenge books usually get reviewed.
2. Current. How current a book is is also important. I try to review titles I think my readers will like and that I like. After months of blogging you learn which books are popular and have more of a buzz on them and sometimes I try to make sure I review these titles too. 
3. Exposure. I choose books to review also based on the amount of exposure they're getting- or not getting. If I see a book that I read and enjoyed but I haven't heard much about it I'll probably write a review about it. While following trends is cool, I like to spread the word on titles not as well known. 

That's what I factor in when deciding whether to review a book. What do you consider?