Groupees Build a Doujin Bundle (LIVE NOW)

I would guess that the eXceed series could be one of the bonuses. I think they were in another bundle not long ago.

More incentive on the other end.

If they had went Fixed, this gap would force more of those on the fence to buy, or nobody would get anything.

There are various psychological reasons for why an all-or-nothing campaign will draw more donations than flex funding.

There is the aspect of the "goal". The campaign organizer is saying that they need a specific amount of money. Flexible funding says "We need X dollars, but we'll take whatever you give us anyway" and that can rub people the wrong way. Did the organizer really mean that they needed X dollars, when they are willing to continue even if they don't get it, or did they just make up a number?

Related to the goal, there is donator safety. Both are fine once the goal is met, but what about when the goal isn't met? With an all-or-nothing campaign, donators lose nothing. With flexible funding, donators are still out their donated money. But will the organizer actually continue if they didn't get the desired amount of funding? The organizer who sees his $100,000 campaign end with only $10,000 in donations may be struggling even for motivation. If the project does continue to completion, then how long will it now take and what compromises might now be made due to lack of funds? A donator decides that he's willing to give $10 for a 10 chapter project with a release date set one year in the future, but what if the project doesn't reach its funding goal and gets cut to 7 chapters or delayed two or three years? Campaigns might promise that a project will continue if funding isn't met, but the donator is now also committing to potentially pay for a more vague solicit of "some form released at some time", at least until the goal is met.

There is the aspect of faith in the project. When an organizer chooses flexible funding, they imply that they don't have faith that their project will meet its goal. While the chance of failure is a reality with any project, and you may be able to successfully continue without full funding, you don't necessarily want to present the image that you don't have faith in your own project. This can turn people off.

You lose some measure of the last minute push to succeed. For projects that go safely into their stretch goals, this isn't an issue. But there are plenty of struggling Kickstarters that see surges in the final days, where donators decide that they are willing to donate a bit more to see a project live rather than die, fence-sitters make their decisions, and people potentially work harder to spread the news of the project to get that last bit of funding (which can result in a substantial jump in funding for some campaigns). That incentive isn't there for flexible funding campaigns because donators know the organizer is getting the money regardless of whether they meet their goal.

There are other issues at play as well, but I've already written quite a bit.