How to get discovered

I wrote a book The Lipstick Murders and published it over a year ago. I'm still trying to figure out how to get it discovered. I think its a great story and I really believe in it. I've tried give aways and other things but nothing seems to work. The problem is I can't afford to spend a lot of money for ads and I'm not real sure how well the ads work anyway. Any suggestions.

The Lipstick Murders.