Put ad spend beside your earnings.
See which books and series are recovering their ad spend, and how much they're earning beyond it.
Switch from books to series to include the earnings from later books alongside the cost of promoting the first. The earnings come from your publishing accounts.
Follow the results over time.
Check a recent promotion or look back across your imported history. Use the same dates and book groupings for your earnings and advertising, so you can see them together.
Net earnings is your publishing earnings minus ad spend. It doesn't include your other publishing costs.
Promoting a series? See what a new reader could be worth.