Fewer than half of those who use price comparison websites are satisfied with the service provided, according to a consumer group's poll.
The 46% satisfaction rating is 2% lower than a previous poll in September 2009, the survey by Which? found.
The websites are used by consumers to compare a range of financial products, such as insurance and energy.
Three-quarters of the 1,703 people polled used such websites, with half taking out a product through them.
Others went back to the provider to buy the product rather than clicking through the comparison website.
There was still some suspicion that these websites only included products that made them the most commission, rather than what was best for the customer.
"Comparison websites are part and parcel of renewing insurance or finding new financial products, so they really need to do a better job at keeping their customers happy," said Peter Vicary-Smith, Which? chief executive.