If you're an author on Goodreads, you can set up ad campaigns for your books. I recently completed a campaign for Lyon's Legacy, so I thought it might be useful to share what I learned from it.
1. It's fairly easy to set up a campaign from the author dashboard, but you do need to have an IBSN associated with your book so you can display the cover with your ad.
2. One of the nice things about ads on Goodreads is that you can target not just genre readers, but people who read e-books as well.
3. Figuring out the cost of the campaign is a bit backwards: instead of specifying how much you want to spend, you have to state how much you want to spend per click (the more you spend, the more often your ad is shown), how much you want to spend per day, and how long you want the ad to run. From those numbers, you then get a cost of the campaign. You do have to pay all of the money up front, but then it's credited to your account. Money is taken out of your account only when someone clicks on your ad, so it's possible to have 1,000 views of your ad but no clicks. It's also possible to set a short time for your campaign but then have it run much longer if you don't reach the capped number of clicks every day.
4. You can run multiple ads in the same campaign. I had one ad linked to Amazon and the other linked to Goodreads (so people can add the book to their shelves). Each ad can have different copy.
5. For me, I found the most effective ads (the ones that got clicks) quoted parts of reviews in my ads. I did vary the wording and headline from time to time to keep the ad fresh.
6. It's possible to pause the campaign if you wish. I stopped the ads for the month of December, when I put my book on sale, because it didn't make sense to spend $0.50 per click when I would make less than that per book.
7. Was it worth it? I can't trace any sales back to the ads, but the ads had over half a million views over the course of the campaign, so at least it raised awareness of the book. I think they may have encouraged a few people to add the book to their shelves. I'd like to try a Goodreads giveaway when I have paper books and see if that's more effective.
If you have any questions about ad campaigns on Goodreads, please post them, and I'll do my best to answer.