A lot of the contents of the book and the add-ons could have used some more promotion. Hopefully the Frog Gods will come out in the next few days and hype this up a bit by giving us some juicy teasers of what we can expect. However, I'm not worried.
Comparing this to the Blight kickstarter it's important to keep some things in perspective. The Blight was a longer than usual project and still didn't fully fund until the 53rd day when there were 5 days left in the campaign. And in those last 5 days The Blight received 32% of it's backers and 43% of it's total funding.
A lot of people just hit the "Remind Me" button on kickstarter and jump in at the last few days. When this happens the project starts hitting it's stretch goals and those hundreds of people who are already backers start upping their pledges to cover the costs of additional add-ons. This has a snowballing effect of unlocking more stuff for people to pledge additional money for.
If I were to make a prediction, I'd say it's going to gain 720 backers and make at least $110k.