I was just listening to an interview with a man named David Siteman Garland who told how his book "Smarter, Faster, Cheaper: non-boring, fluff-free strategies for marketing and promoting your business" came about.
He had a podcast on which he interviewed a lot of authors. Those authors told their publishers about the exposure they were getting. One of the publishers approached Garland and suggested that he write a book for them (see www.smarterfastercheaper.com).
He didn't use this as a deliberate strategy but seems to me there's the seed of one in there.
If you had one specific publisher in mind, you could even target it by interviewing their authors, or you might cut across a number of publishers but focus on the genre that is closest to your own book's.
(for more tips on writing and marketing your book, see "Your Writing Coach," published by Nicholas Brealey Publishing, and "Marketing for Entrepreneurs," published by Pearson. Both are available from Amazon and other online and offline booksellers.)