Mergers – increased merger activity will allow authorities to examine the competitive dynamics between online and traditional retailers in more sectors. The approaches taken in these cases is still developing.

In the UK, for example, the Competition Commission is considering whether online gambling exercises a competitive constraint on bricks and mortar casinos (eg Rank/Gala), having previously found that internet sales are increasingly acting as a constraint on high street travel agents (eg Thomas Cook/Co-operative Group/Midlands Co-operative).
Read on-
https://competitionindia.wordpress.com/2014/08/19/online-retail/