Coming soon to this blog.... Mary Hoffman talking about her new novel David, published in July.
That's a blog tour in action.
Publishers used to pay for (some of) their authors to go on book tours. In these straitened times, book tours are out except for the very big names, and many writers instead do a blog tour. It's free, it's easy, you can do it from home; you don't sit for hours in a bookshop waiting to sign books people don't want to buy, your luggage doesn't get lost and you don't spend sleepless nights in dingy hotels. What's not to like?
A blog tour is simply a series of guest posts on other people's blogs. The blogs should be relevant, of course. If you've written a young adult dystopic novel, you won't want to guest on a blog about sparkly mermaid stories (unless the initial catastrophe in your novel involves sparkly mermaids, I suppose). Your post should be relevant to the blog in some way, too. If the blog is about getting published, maybe post about how you first got published, or the genesis of the new book, for example.
The idea of a blog tour is to introduce your writing to new readers, so try to think outside the usual round of blogs followed by the same people - mix and match. Review blogs are obviously a good idea, but what about teachers' blogs, or blogs related to the subject of your book? If you've written a story about hockey players or Vikings (or hockey-playing Vikings), perhaps find blogs about those and ask if you can do a guest post on researching and writing about the topic.
A blog tour has a planned itinerary - the list of blogs you will visit - and often a banner or badge the host blogger puts on their blog. The banner or itinerary can link to other blogs in the tour. This promotes your other posts and also promotes the host blog.
Many authors organise their own blog tours, as they're often a lot more tech savvy than their editors and publicists. The author is usually better placed to know which blogs will make the best venues, too. Unless your publicist (if you have one) is particularly on-the-ball, you might just like to tell them what you're doing so that they can publicise it through the usual channels, but get on with it yourself. If you aren't up to the image processing needed to make a banner, you could ask the publisher to do that. Or ask me. Hmm. I could set up a blog-tour banner business now there's no money in writing....