Why use conversion ranges?
One assumed conversion rate can hide how sensitive your launch plan is. A low/high range keeps that sensitivity visible while the audience is still being built.
Avoid double counting
Email subscribers may also follow the Kickstarter prelaunch page or hold a reservation. Use mutually exclusive rows where possible, or reduce overlapping counts before reading the total.
Replace assumptions with actuals
Use the Follower Growth Tracker while building the audience and the Funding Pace Calculator after launch.