Google is hoping to make mobile advertising more appealing to brands with the launch of four new display ad formats created specifically for mobile devices, as it admits that some brands are struggling to engage with consumers via mobile. Rolling out globally over the coming two months, including in the UK, the formats are all designed specifically for mobile. The full-screen ads will appear in apps at logical points such as when clicking into an article on a news app or between levels of a game.

A pilot scheme to introduce age ratings to online music videos is to begin on Friday as part of moves to bring the industry into line with film and television. Sony, Universal and Warner Bros have all signed up to the initiative with YouTube and Vevo also getting on board, although the scheme will only affect artists signed to UK labels for now. The new system is being overseen by the British Board of Film Classification, which will dole out the PG, 12, 12A, 15 and 18 certificates familiar to movie buffs.

Social news site Reddit has raised $50m from stars such as rapper Snoop Dogg and actor Jared Leto, in a deal that will see investors giving 10pc of their shares back to the site's user community. The funding was led by Sam Altman, president of Y Combinator, the incubator that originally helped launch Reddit. The nine-year old service plans to use the funding to expand its staff of about 60, to work better with third-party developers, and to expand its mobile app, among other things.

Sky has invested GBP5m (GBP3.1m) in native advertising technology business Sharethrough. Its software provides advertisers with an automated system that matches online ad campaigns to the Web pages they are appearing on, enabling publishers to monetise platforms and apps. The investment follows an earlier arrangement between the two parties, whereby Sky worked with Sharethrough to offer native advertising on skysports.com.