The OFT is launching two separate market studies into advertising and pricing.
The first, into online targeting of advertising and prices will cover behavioural advertising and customised pricing. This study will be completed by spring 2010.
The second, into advertising of prices, will consider various pricing practices that the OFT said "may potentially mislead consumers". The OFT added that the study will look in particular at how these practices are used online.
It will examine practices including "reference prices", where there is a relatively high reference price compared to sale price, for example "was £50, now £20", or "50% off". And it will look into practices such as "time-limited offers", including sales that finish at the end of the month or special prices that are available for one day only.
This study is expected to be completed by summer 2010.
Heather Clayton, OFT senior director, said the studies would ensure regulators kept up to date "on how new pricing and advertising practices are emerging and evolving online".