BT's Twitter competition plays cupid and encourages romantics to tweet their messages of love to the top of London's BT Tower.
But an ad for Ikea in Australia has become a social media hit, offering free cots to babies born nine months after Valentine's Day.
Supermarkets and retailers, including Tesco and John Lewis, have also taken the opportunity to promote flowers and gifts to last-minute shoppers.
Cadbury has a Promoted Trend on Twitter and other brands offering 140 character love notes include Citizen Watches, Royal Mail and Now TV.
This article was first published on campaignlive.co.uk
A useful study here from the ‘Pew Research Center’ taking a look at the demographic make-up of US social media users across Twitter, Tumblr, Pinterest, Instagram and Facebook. No data on LinkedIn of Google+, but great stats all the same.