Credit unions may have access to mountains of data, but 59% of their members apparently feel retail websites such as Amazon, Netflix and Zappos know them better than their credit unions do, according to a new survey of 2,201 U.S. adults by financial services software company Segmint.

The results of the online survey, done between March 23 and 27, also suggested that other kinds of financial institutions know their customers even less than credit unions do. Overall, 64% of all U.S. financial institution customers said their financial institutions don't know them as well as retail websites do. The number was 60% for local community banks, 64% for regional banks and 66% for customers of big national banks. It hit 83% for customers of online-only banks.

"Financial institutions are sitting on a gold mine of customer insights to help them better guide their customers through their financial journey," Segmint President and CEO Rob Heiser said. "Listening to customer's transaction data will help banks build meaningful relationships with their customers while earning a greater share of their wallet."