To be honest, everybody(and I) hates survey sites, like where your eBook is uploaded to. When I see survey sites (like yours), I will hit the X button right away, without any hesitation. If you are really serious and willing to share, upload it to other sites that you can earn and without all these surveys.
I will never download stuff from survey sites. If you want some return, make it more meaningful.
Give away the eBook for free and make a donation page for people to donate.
If your ebook is good enough(and available for free at the same time), people will appreciate your effort and donate to you.