I have never been terribly lucky in any other thing I've tried, but I've been extremely fortunate in the mystery awards department. From the very first book in my series, Sympathy For the Devil , which came out in 1998, I have had the great blessing of the positive reaction of readers. In fact, all three of my books have been recognized with Agatha Award nominations. I'm just so grateful to those who bought and read my books and have supported the series. As for what an award means in terms of sales, it is hard to say exactly.
Awards certainly help an author get noticed by fans and by mystery booksellers.
It is a lovely thing to put a nomination or award on the cover of a book, which might help a reader pick it up and consider trying it. It also helps an author get additional attention from her own publishing house. That notice may translate into more support and promotion. But most of the big publishers are only looking at an author's sales numbers, and even award winners can see their numbers drop. It's a hard cold commercial world, so I try not to worry about what I cannot control.