Yahoo's shares plunged today as the cyberattack that saw details from a billion accounts stolen threatened to derail the $4.8bn (GBP3.9bn) deal to sell the Internet company's core business to Verizon. The US telecom giant is believed to be prepared to back out after Yahoo revealed a record-breaking hack for the second time since the two companies reached a deal five months ago.

Rupert Murdoch's 21st Century Fox has formally lodged its GBP11.7bn bid to take full control of Sky, as minority shareholders call for transparency on how the pay-TV company's independent directors came to accept the offer. Murdoch will now need to gain regulatory approval for the deal, which values Sky at more than GBP18bn.

Amazon has announced that its drone delivery service is now live in the UK and has completed its first delivery. The retail giant said the first delivery was an Amazon Fire TV Stick and a bag of popcorn that was carried to a customer in Cambridge. Apparently, it took only 13 minutes from clicking the buy button on the website to having the order at the door.

Major League Baseball wants to become the latest American sport to make inroads overseas, having met with various UK PR and digital firms in recent weeks. American football and basketball have both upped their presence in the UK capital in recent years, with an increasing number of NFL and NBA regular-season games hosted by the city.

Manchester United has teamed up with music streaming service Deezer in a partnership that will see current and former players of the club take part in a digital campaign. The campaign launched this week across the social media channels of both partners, will star Jesse Lingard, Paul Pogba, Morgan Schneiderlin, Ashley Young and Rio Ferdinand.

The Guardian has launched a new native advertising offering, Hosted by the Guardian, allowing brands to host their own content on site instead of working with the publisher to align themselves with editorially led native features. This means advertisers create the content themselves, instead of the publisher creating content on behalf of the brands in a native editorial format.

Yahoo has said more than one billion user accounts may have been affected in a hacking attack dating back to 2013. The Internet giant said it appeared separate from a 2014 breach disclosed in September, when Yahoo revealed 500 million accounts had been accessed. Yahoo said names, phone numbers, passwords and email addresses were stolen, but not bank and payment data.

Gordon Brown has demanded that Rupert Murdoch's takeover of the Sky satellite business be delayed until the government carries out the second part of the Leveson inquiry into press malpractice.

Almost half of online campaigns don't reach their target audience. A study conducted by measurement company Nielsen found that UK campaigns reach their target just 47% of the time. Travel brands are the most successful at reaching their desired audience, at 66% of the time. Entertainment came in second at 64%, while FMCG and retail struggled, at just 40% and 42%.

The Lad Bible group has launched a "branded entertainment" agency called Joyride to help brands reach its portfolio of sites, including the Sport Bible and Pretty52. The publisher has poached Ian Richardson from Vice Media to run Joyride. Richardson was formerly UK head of Virtue, one of several Vice Media agencies.