Links appeared as part of Google's effort to provide fact checks and fight misinformation.
YouTube house promotes platform's growing list of offerings.
Huffington Post journalist Alexander Kaufman tweeted about the company-wide email but has since deleted it.
Ads are already available on sister Instagram Stories platform.
Despite some other positive indicators, Twitter's share price fell 14% as the platform revealed a dip in its monthly active
Facebook has suspended around 200 apps from its platform, as part of an investigation into the misuses of data carried
Refinery29, the digital media company, is expanding its 29Rooms exhibition across the US.
Google parent company Alphabet reported revenues for the first quarter of 2018 up 26% to $31.1bn (£22.4bn).
In the next few weeks Facebook is to propose updates to its terms of service and to its data policy
Being nimble has enabled the media outlet to stay ahead of the game without compromising on voice or style.