That's crazy high number, so I decided to share my experience and would love to hear your stats!
Dropped pledges can happen in two phases:
- During the project, when backers cancel their pledge (the one that you are referring to)
- After the project, when Kickstarter isn't able to process backers' credit cards
- 0.5% backers (1 out of 200) cancelled their pledges during the campaign
- 8% dropped backers (16 backers out of 200) after the campaign
- 11% backers (7 out of 62) cancelled their pledges during the campaign
- 13% dropped backers (8 out of 62) after the campaign
As for the dropped backers after campaign is finished, you can't control that much as Kickstarter uses Stripe to process credit cards. However, you can approach those backers directly and propose them to use PayPal to pay for your reward.
What are your stats?