Advertisers on the Web are in a quandary. They want to deliver personalized ads that consumers will act on, but Internet users don’t want their browsing activity to be tracked.

A recent study by IAB quizzed 2,000 people on their attitudes to online ads, privacy and cookies, the small pieces of code that track what someone’s looking at on the Web. More than half (55 percent) of the U.K. consumers polled said they want more relevant ads, yet just 21 percent are willing to consent to cookies tracking their moves and finding out what they’re interested in.

Only by understanding what people like can advertising companies present more relevant advertising to them. Though many people freely provide their hobbies and culture preferences to companies like Facebook, cookies are an important way of discovering the interests of Web users.

Meanwhile, 52 percent of consumers surveyed said they’re happy to see ads, as they’re understand that advertising otherwise allows them to view high-quality content for free. While that indicates almost half don’t want to see ads, just a tenth of respondents said they’d pay up in order to access ad-free content. Six out of ten said they understood that much of the content they view on the Web would vanish if not for advertising.

Not all respondents were therefore certain what a cookie actually is. Almost two-thirds (64 percent) said they were confident they know what a cookie is. But just 57 percent of those selected the correct definition from a number of options given to them.

Effectively, 39 percent of those who deleted cookies in the last six months did so without a firm understanding of what cookies are and what their purpose is.

With legislators all in a tizzy over how advertisers track Web browsing activity, this cookie issue is not one that’s likely to be resolved by the Cookie Monster anytime soon.