Mobile phones are quickly becoming the up-close-and-personal marketing medium. And the possibility of knowing a person's location at any given time through the websites they surf or mobile applications they have visited on their smartphone's browser is opening a new world of possibilities for marketers.
Both Google and Facebook have launched services that broadcast your location to friends - Latitude and Places respectively.
They even have plans to allow participating retail outlets, restaurants and cafes to offer special deals to Facebook users who "check in" with them.
"Location will be one of the cornerstones of mobile advertising. Merging local businesses with mobile [advertising] is very, very important for us," the Sydney Morning Herald quoted Michael Slinger, director of mobile advertising at Google, as saying.
Graham Christie, the commercial director of the mobile marketing agency Big Mobile, says people should be pleased rather than perturbed at the prospect.
Simply because this pinpoint targeting will avoid bad and irrelevant advertising.
"We can give people more of what they want, when they want it and less of what they don't want. It takes the guesswork out of a lot of advertising," he said.
One such kind of advertising - behavioural targeting - is already practised on the Internet.
The user's identity is never revealed and the segments of consumers are sold to advertisers who match their needs with their marketing messages.
Jamie Conyngham, a mobile apps developer, says, ''if you can get very specific about their tastes you can really tailor discounts to them or up-sell them something, or work out what it is that they might want that they didn't know they needed yet."
"If you look at the internet and mobile phones, it's really only the simple things that work. 'When Amazon reduced the number of clicks it took to buy a book or a DVD, they saw their business grow. Mobile needs to be even easier than that," he added.
Privacy experts such as Colin Jacobs of Electronic Frontiers Australia say, inevitably, people will compromise their privacy.
"It wouldn't take long to work out where you are and where you live. I'm not suggesting that someone is going to fire a missile at your house but finding out where you live is very sensitive information to be handled by third parties. I think we'd better get used to living in an age of less privacy," he said.