We are also Amazon FBA sellers. Our products came out of the frustration of not having a tool for FBA to track our data that wasn’t $50+ a month. Not to mention, with those services you’re basically handing over your data to anyone that works there. We really wanted something we could control and easily have available.
The spreadsheets that were available were fundamental, and a lot of data had to manually be entered. Knowing what we know about Excel, and what it can do, we started working. The Ultimate FBA Sales spreadsheet took about a month to get to something that worked. Initially there were so many formulas that the spreadsheet was freezing every time something was changed. We had to rework everything using different methods, like pivot tables and macros to do some of the heavy lifting. We continue to add features and optimize the code in all of our products.