Book publicity: how much & what works?

I believe that, unless sales are through the roof, authors can't do enough to get the word out about their books. But what works for one author might not work for another, and we must balance time spent with cost, and still make time to write and release new product.

Do I currently have a formal marketing plan? No. Do I try to stay on top of promotional opportunities and regularly promote to develop a great mix of reviews, blogs/articles and ads? Yes. Of course I'd love huge sales increases, but I've read that the frequency of impressions needed to get people to take action has increased from seven to 10. So I'm focusing on growing awareness

Here area few recent and upcoming results:

THE BRIDE TOURNAMENT  received a great review from Publishers Weekly, and is currently front and center on Booklife.com. Highlights: "Kaufman hits her stride with this enjoyable third entry in her War of the Roses Brides series...."  "Appealing protagonists, a satisfying pace, engaging supporting characters, and numerous obstacles to overcome combine in this emotionally satisfying romance."

A post about TBT on Romance Lives Forever was tweeted and retweeted for several days. I stopped counting when the total reach passed 630,000!

And coming March 2: my first BookBub, such a popular and selective discount and free book daily email that I've been refused multiple times (as have many other authors I know). It costs hundreds of dollars, depending on your genre and countries you wish to include, but word on the street is that the thousands of downloads make it worth the price.

This and other promotion will be in conjunction with making AT HIS COMMAND free for 5 days. How many downloads will I get? Will sales of my other books increase? Stay tuned!