Regulation of online advertising, in particular of new formats such as user-targeted ads, will be one of the 'bigger issues in the market going forward', Waldman (pictured left) told attendees of the Westminster eForum on online advertising.
Earlier this year the Guardian pulled out of talks with targeted advertising firm Phorm, citing a clash with the publisher's values as its reason.
"The issue of privacy is going to rear its head and I hope there's an intelligent approach to it and not scaremongering," he said.
According to fellow speaker Guy Phillipson, chief executive of the Internet Advertising Bureau (IAB), audiences need to be better educated in how targeted and behavioural advertising works.
Users need to understand that sites do not 'know' who the consumer is, but that user data is instead stored in 'anonymous cookies' [text sent between by a server to a web browser containing information on a user's site preferences], Phillipson explained.
In terms of collecting data about site users, Waldman said there was an interest in investigating readers' behaviour both on and off Guardian.co.uk.
"The pattern of behaviour is one of the more interesting things we have to crack as a publisher because it's completely different to print," he said.
However, he said, without an industry standard for delivering data on online user behaviour, any information currently provided will be 'a jigsaw of apples and oranges from one business to the next'.
Dominic Carter, trading director at News International, said his employer was collecting a lot of data about site users.
"We have, as a business, just over 13 million names and we're using the relationship that we have with them online to build that data. What we're trying to do is find out definite information about them," he said.
"It's about liaising and having a dialogue with our consumers. That dialogue is allowing us to have a lot more information about where they are in life, about where they are in purchasing cycles in terms of cars, houses, investments," he said.
"[W]hen we start to get a lot more depth we'll start to release what we know about our consumers."