Promotion is all about getting your name "out there". If readers keep seeing your name come up while they're surfing there's a chance they may be curious enough to buy your book when they walk into a bookstore and see your name yet again.
Some authors choose to build a platform around educating other writers and many can provide excellent advice on how to write and/or negotiate the publishing realm. It's all very well marketing to other writers since writers love to read, but think outside the box too - what do your other potential readers want to know? Haul out the research you did for your book. If you wrote a cosy mystery around a quilting circle, write articles about quilting, post any patterns you created for your characters or links to patterns you found online, and post the recipe for the Death by Chocolate dessert that your victim was killed over (sans cyanide, of course). If you researched sixteenth century Eastern European culture for a historical novel, post a list of little known facts, link to pictures of costumes from that period, and write about the politics, or the jobs people did, or the harshness of the legal system at the time.
The idea is to think backwards: if someone is interested in fly fishing and finds your article on tying the perfect fly, they may be intrigued that you wrote a literary novel centred around the deep philosophical insight gained on a fishing expedition. Likewise, with the holidays coming up, someone searching for gift ideas for golfers might consider a novel featuring a golfer who solves gritty suburban crimes to be a more interesting gift than a book on perfecting your swing.
As you saw in the previous post, Wikipedia is one of the most reliable sites on which to have your profile. It is not, however, ideal for publishing content. If you choose to help edit pages or create new information pages, your expertise is not directly credited to your name so the promotion currency is lost. Also, Wikipedia discourages publication of original research or linking to your own content.
Hopefully this has given you some starting points for brainstorming your approach to developing the content that will build your online platform. Do you have any tips of your own to share with us?
Using Web 2.0 Content Sites to Expand Your Platform
Building an Online Platform to Promote Your Books
Elsa Neal was one of the early adopters of Squidoo after it came out of Beta and has been actively involved in the community as a Squid Angel and a Top 100 Giant Squid. She has more recently been experimenting with HubPages. She can also be found on her own website or sharing her writing insights at her Fictional Life Blog.