The campaign, which kicks off this weekend at Westfield shopping centre in Shepherd’s Bush, is the first integrated campaign Yahoo has run in the UK to promote omg! since it launched in July last year.
The campaign was created by Pitch, which also handled experiential and PR. MediaVest handled social and digital, and CBS the outdoor element part of the campaign.
Shoppers will be able to queue on a pink carpet before having their photo taken in a photo booth, pulling their best "Oh my God!" face.
On 13 and 14 October a number of celebrities will turn up to surprise participants.
Their faces will appear on digital screen in the shopping centre and they can share them on Facebook.
In addition to the experiential activity, Yahoo is encouraging fans to post their omg images on omg!’s Facebook page via an app. The best image will win a £3,000 voucher for online fashion retailer Asos, and there will also be two £500 Asos vouchers for runners up.
The competition closes on 15 November. The campaign will be supported via a promoted Twitter campaign, Facebook media, editorial coverage on the omg! Site, as well as online ads across Yahoo's network.
The last ad campaign Yahoo rolled out was to promote its sport content, during the Olympics.Follow @shearmans