I received a really nice review for Gumbo Justice from Martha Cheves on her website, A Book and a Dish, www.marthaskitchenkorner.blogspot.com. Martha writes cook books, one in particular is my favorite, Stir, Laugh, Repeat, which has easy to make recipes, and she also reviews books. The combination of the two is quite interesting. I submitted a New Orleans recipe for Corn Soup, which is also posted. Martha also posts her reviews on other websites, such as Amazon, Barnes and Noble, etc..
She seemed to have really enjoyed my novel, which of course made me breathe a small sigh of relief. So far, a lot of my friends and family have bought my book, but most are still in the process of reading it. The opinions of those close to you are hard to take seriously anyway, because (1) they are predisposed to love your work; and (2) they are predisposed NOT to tell you if they don't love it. So getting a favorable review from someone who doesn't know me, and has no reason to pretend she loves my book if she doesn't, is validating.
I try to do reviews for people I know on Amazon whenever I can. I know if I happen to stumble across an unknown writer or unknown title that looks interesting, I usually will read the reviews before I decide to commit my money and time to the purchase. If the book has no reviews, I generally won't buy it. So it may help a lesser known author make a sale if the book has positive, informative reviews.
Also, on Amazon, if you run across a book or author you like, add tags for them. Tags help the books show up on searches, as do Listmania lists. If you make a list on Amazon, such as "My Favorite Murder Mysteries," and include the title of an unknown author, and then add a famous author in the genre and maybe a mid level popular author to the list, there is a chance online shoppers who look up the more famous author will see one of these lists, read it and see the unknown author's book. While there are numerous lists and tags out there competing for attention, it only takes a few minutes to help out an unknown author and could result in more people seeing the work.