1. Who is your reader? Marketing 101 clearly states, "Define your market." Regardless of what your genre you need to define your market. Sadly, a common answer when you ask some authors who would read their book is, "Everyone."
Not so. The more you pinpoint who your reader is the easier your marketing becomes. Simple as that.
2. Where does your reader hang out? What this simply means in the world of online book promotions is knowing what social networks they frequent, what forums they enjoy and what blogs they tend to read.
Let's say you're authored a book on the care and training of Boxer dogs. You'll be well served to find groups in social networks that have a high concentration of Boxer dog owners. There are lots to choose from.
Next, find forums specific to Boxer owners. Again, there are many available. Some have such incredibly high numbers of members that you would be making a huge book marketing mistake to not be an active and contributing member of such a forum.
3. Have a plan. How long do you plan to set the stage for an online promotion for your book? The fact is, the more you lay a solid foundation over a period of time the greater your success. Don't expect to set up a profile in a social network one day and begin promoting your book the next.
Sure some authors do this, but I daresay their results will be minimal at best.
Invest time and energy into your online book promotions to gain optimum results.