(This version of the story corrects throughout to show timeline changes do not affect paid ads)
By Yasmeen Abutaleb
Twitter Inc made a dramatic product change on Wednesday, saying it will recast the way it displays tweets on its homepage by customizing them to individual users, instead of uniformly displaying tweets in reverse chronological order.
The change to the timeline - as the main page is known - is also designed to appeal to advertisers and brands by giving more prominence to high-quality tweets from their accounts, but they cannot pay to have their tweets surface higher.
The change comes just hours before Twitter reports fourth-quarter earnings to investors, who have been pressuring the company to increase user growth and ad revenue by making the product easier to use.
Reports that Twitter could be changing the timeline surfaced last week, prompting laments by users tweeting with the hashtag #RIPTwitter. They said using a customized, or algorithmic, timeline - similar to Facebook's News Feed - meant Twitter would lose one of its signature features.
In testing the new timeline, Twitter wrote in a blog post that it saw increased user interaction with advertisers' tweets and tweets about live events. Advertisers have said their ads can get lost in the reverse-chronological timeline.
Twitter said it analyzed how users have engaged with billions of tweets to determine what they are most interested in.
When users open their timeline, they will see several tweets from the past several hours that Twitter thinks they are most likely to interact with. Underneath it they will see the traditional reverse-chronological timeline.
Users can choose to opt out of the new algorithmic timeline.
Jack Dorsey, Twitter's chief executive and co-founder, tried to reassure users in a series of tweets last week that Twitter would remain the place for live news and commentary.
"Twitter is real-time. Twitter is about who & what you follow. And Twitter is here to stay! By becoming more Twitter-y," Dorsey wrote. "We're going to continue to refine it to make Twitter feel more, not less, live!"
(Editing by Stephen R. Trousdale and Leslie Adler)