Most online consumers don’t want to share personal information in exchange for retail offers, suggest U.K. survey data commissioned by London-based e-mail services provider Emailvision Holdings Ltd.

Only 28% of respondents said they would share their names with brands in exchange for “better targeted offers.” 37% would share their ages and 38% would share their genders, the report says. “This lack of sharing demonstrates that consumers online don’t yet see the value of exposing their information to brands,” the report says.

That’s not to say every consumer fears giving away personal information. 8% of respondents would “go as far as to disclose their underwear size in exchange for better targeted offers from a brand,” the report says.

The findings are based on an online survey of 2,001 U.K. adults conducted between Nov. 2 and Nov. 5, 2012 by YouGov plc.

The survey findings suggest that consumers may be wary of sharing information with brands because of previous errors. 50% of respondents said they’ve received e-mails with their names listed incorrectly, with 40% reporting gender mistakes.

The report also found that too many e-mail marketing messages can turn consumers against brands. 75% of respondents said they would “resent a brand” that sends too many e-mails, while 71% disliked being sent unsolicited e-mail messages. The report did not define how many e-mails are too much.