Effective book publicity campaigns get the word out to target audiences and are very beneficial. However, word of mouth continues to be much of the most potent promotion, and book clubs will do it. Club members are generally devoted readers, and when they enjoy a book, they tell friends, family, and co-workers and often post about it online. Getting that kind of endorsement from a group of people simultaneously can lead to multiple copy or download sales. It's also a way to get the algorithms of large online sites recommending your work to their browsers. However it happens, it is beneficial to your sales.
Getting book clubs to read your book can be a function of outreach and making it easy for them. For example, it's increasingly common for authors to include club discussions at the end of their books and eBooks. You can also add a page on your author's website with questions and information for club readers. It's a small and inexpensive thing that can bring significant results. As it launches, you can proactively reach out to club leaders with pitches and a free copy of your book. Once you become a club favorite, members will likely watch for future books you write and be eager to read them.
It's wise to explore group sales options in any business; books included and book clubs allow you to do it naturally. Selling single copies can add to respectable totals over time, but you can increase your sales volume much faster with group sales. Profitability depends on achieving your planned sales volume, and when you can score group sales successes, you'll make your numbers easier. That's why book club outreach is wise. Some authors now go as far as appearing virtually with club members, planning an online live stream, and inviting multiple clubs to attend. It's an excellent publicity vehicle for you.
If you're a profit-minded author self-publishing your work, look for book printing and fulfillment services. They allow you to print your books conventionally so that you can sell them in all retail channels (online and brick-and-mortar). If you go with on-demand publishing, you may be limited to online selling in certain spots. There are also some surprising bookselling opportunities like big box stores and their book aisles. They might not be the first places you think of, but the sales volume is significant. Book distributors can help you get onto their racks. It requires publishing your book to the highest standards.