My former professors told me they earned $5-$50 per survey and surveys filled the inbox everyday. They never did all in one day, but 4 surveys per day, each $10 or $15, gave them something significant.
One of my high school classmates did this program. He always did 6 surveys a day, and did 2 product reviews each week, making him around $4,200 a month, and I asked him how, so he showed me.