The Office of Fair Trading this week launched a probe into how businesses are monitoring online shoppers and using the data to target them with personalised prices, and whether any action is necessary under the OFT's powers.
Cookies and other data storage now enable businesses to monitor consumer behaviour, collecting information about shoppers' purchasing habits, websites they have visited and the items and services they have looked at, as well as the device or internet browser they use.
The OFT said it "will look at how businesses use such information, including whether they change the prices they offer individual shoppers as a result".
The regulator will consider business and technological developments in the online shopping market, consumers' understanding of how their information is used, and whether they are being treated unfairly in law as a result of any firms using this practice.
The OFT will consult international counterparts including the US Federal Trade Commission on commercial uses of consumer data. Clive Maxwell, the OFT's chief executive, said: "Innovation online is an important driver of economic growth.
"But the ways in which data is collected and used is evolving rapidly. It is important we understand what control shoppers have over their profile and whether firms are using shoppers' profiles to charge different prices for goods."
Meanwhile, the Financial Services Authority has warned that companies using social media "often fall foul" of the rules on financial promotions, and risk regulatory action.
The FSA's head of asset management Ed Harley told a financial conference that the rules applied across all media. Firms often "do not realise what they are tweeting, for example, can be an inducement to invest or engage in financial services". He said the new Financial Conduct Authority would have stronger powers to ban adverts and publicise wrongdoers.