Marketing Performance.
Data-driven decision making for the modern growth architect. Master your acquisition costs and visualize the true profitability of your campaigns.
ROI Analytics
Calculate the Return on Investment for any project or campaign. Compare your net profit against costs to see your exact percentage growth and multiplier.
Launch ToolAd Spend Engine
Analyze your advertising efficiency. Solve for CPC, CPM, or CPA instantly. Input your total spend and results to discover your acquisition heartbeat.
Launch ToolResearch & Notes.
In-depth articles on the math and logic behind our tools — written for people who want to understand the calculations, not just run them.
How to Calculate KDP Spine Width Without Getting Your Cover Rejected
A spine width miscalculation is the single most common reason KDP rejects a cover file. Here is the exact formula, the constants, and the edge cases that trip up most authors.
KDP vs IngramSpark: Which Pays Better Royalties in 2026?
Both KDP and IngramSpark promise broad distribution, but their royalty structures are fundamentally different. Here is an honest comparison of which platform pays more and when.
Why Your Book Spine Goes Blank: The 80-Page Rule Explained
KDP will not print text on spines below a page count threshold. Here is the physics behind why, and what you can do about it if your manuscript is short.