The Office of Fair Trading has started scrutinizing practices used by online shops in the fields of advertising and pricing strategies.

The OFT is worried that consumers could suffer in case information regarding their personal web usage is used to set the price they are offered for a particular product or service. The competition watchdog informed that it would hold two market studies.

One study will probe sales practices on the internet, while the other will examine like 'drip pricing', where the cost of an item increases through the buying process. It may be noted here that some online retailers use behavioural data to set customised pricing.

Heather Clayton, senior director of the OFT, said, "These studies will ensure that we keep up to date with the latest development and how new pricing and advertising practices are emerging and evolving online."

The recent move of the OFT is a part of its wider examination into misleading pricing practices used by both online and high-street retailers.

The investigation into online advertising and pricing is expected to finish by summer 2010.