Ellen Fisher wrote in comments: PBW, I recently read an article about Janet Evanovich, who basically said that selling books is all about taking up as much "real estate" in the stores as possible, which means writing across genres. Since you write in multiple genres too, I'd love to hear your take on this when you return.
The Divine Ms. E definitely takes up major real estate with her Stephanie Plum series and the collaboration romances she writes with other authors, but no matter what she publishes, it ends up on the bestseller racks and in the front of the store. Prime turf to sell books -- but getting there isn't easy.
In my situation, being all over a bookstore doesn't have much impact on my sales. For one thing, despite my presence on the internet, few bookstore patrons are familiar with the diversity of my work. They don't know that Jessica Hall = S.L. Viehl = Lynn Viehl = [Writer-for-hire Pseudonym] = Rebecca Kelly and so on. The most crossover I've seen has been from new readers of the Darkyn books who went and found my SF novels, but the pseudonym surnames are the same, and unusual. If I was writing those books as Lynn Smith and S.L. Smith, they probably wouldn't have found my other novels.
Also consider that for various reasons most publishers don't want writers to use the same name or pseudonym when they write in other genres. If you write in more than two genres, or work for more than one publisher, you'll probably have a hard time keeping the same name on all your books.
What are the alternatives to getting more real estate in the stores? A large print run that puts you in the front of the store is great -- as long as your books sell so you don't have huge returns. These days a 100K print run will not get you in the front of a major chain store. I'd guess it takes a 150-200K minimum. Shelf sitters, book dumps and other eye-catchers might grab some attention, but not enough to spike your sell-through. There's just too much competition.
The publishers and the booksellers are the ones who decide who gets prime store real estate, and it's always the established bestsellers or the rookies who for whatever reason get major backing for their first book. Which we'll all agree is not fair, but that's how this business works.
If you're not fortunate enough to be a BSLer or Elizabeth Kostova, then maybe the best thing you can do is to write the kind of books people want to read. Dazzle your readers, and they will tell other people about your books. Reader buzz is something publishers and booksellers can't generate, buy, control or reserve for their pet authors. It can only be earned -- by great storytellers.