I’m sure there’s an upside to having a base you can send an update to when you open pre-orders, and some folks would argue it’s prudent to amass dozens/even a couple hundred followers before starting a campaign, but I personally believe it doesn’t make the difference between a successful campaign and one that doesn’t make it. The vast, vast, vast majority of my sales were people who followed and ordered the book all at once while I was in campaign mode.

I think if you’re unsure, give your campaign some extra leash. Inkshares recommends 90 days for your campaign, but there’s no reason you can’t go with 120, 150 or even 300 days and then amass followers while the book is on sale. I think there’s a significant benefit to getting people to follow the book when they also can pre-order it, because then they’re making one trip to your page instead of two.