Book Proposal Update

I received this e-mail today:

"The acquisitions editor] received your proposal and reviewed it with the rest of the editorial team. The concept of weaving educational facts in and out of the narrative story was an effective learning technique and the visuals were impressive. We thank you for your interest; however, we are unable to publish your work because it does not meet any of our publishing needs at present. We wish you the best of luck in the continuation of this project."

I am planning to submit it to other publishers before deciding to self-publish.