Facebook is upping the stakes against YouTube with an ad-interspersed ‘Suggested Videos’ trial in the US and the introduction of an option that means advertisers only pay for an ad if it is viewed for at least 10 seconds.

The social network is also testing a ‘Suggested Videos’ feed that compiles a montage of content clips interspersed with ads. It is encouraging creators to make more compelling video by offering more money for longer views, with Facebook keeping 45% of ad revenues.

According to Facebook, its user-generated-content (UGC) video attracts 4bn views every day.

The new video trials are a clear challenge to the online video market’s outright leader, YouTube, whose content archives are rich both in UGC as well as content posted by publishers and media owners. The Google-owned video platform gives users 55% of ad revenues from ads posted before their videos.

Facebook will likewise give 55% of ad revenues to content creators, although because of the composite nature of the Suggested Videos feed, that money will be divided between the various creators.

Those creators are currently Facebook-selected producers, media owners and users, in contrast to YouTube’s approach, which allows all users to monetise their videos.

Facebook’s Suggested Videos is being tested in the US, where separately HBO has said it would stream some of its series on Facebook.

According to eMarketer data, the overall video market was worth $5.81bn in the US in 2014. Globally YouTube earned $7.6bn in gross revenues last year, according to eMarketer, and that figure is forecast to grow 25% to $9.5bn this year.