Twitter is making two major changes to the way its users' timelines appear.
The app will show a selection of prioritised tweets, based on what it thinks users are "most likely to care about", ahead of the normal list of posts shown in reverse chronological order.
And a new First View feature will let marketers place a video ad high up in the feeds.
The announcements came ahead of the company's latest financial results.
They are designed to make users more engaged with the platform and appeal to advertisers.
But one expert said the extra prominence Twitter was giving to video ads might backfire.
"The reason why Facebook has been so successful of late is that it has been able to put sponsored posts and videos into people's feeds," commented Richard Holway, chairman of the TechMarketView consultancy.
"But Twitter is a different affair as people typically spend a much shorter time looking at each post, and putting intrusive videos at the top of their feeds, making it more cluttered, is going to upset a lot of people."
Unlike normal ads on the platform - which algorithms target at specific users - a First View video will be shown to everyone within a region or country who uses Twitter over a 24-hour period.
That makes it a potentially more effective way to build mass awareness of a product over a short period of time.
But another company watcher also expressed doubts about the idea based on the examples Twitter had posted online.
"The whole point of in-feed ads is that they should seamlessly roll through and not interrupt your experience," said Sarah Vizard, Marketing Week's news editor.
"Brands will love [First View] as it sits across the top of the page and everyone will see it, but for the users themselves, they will think: 'It takes over most of the feed. I came here to see what the people I follow are posting and to find information, and to get to that I now have to clear the ad.'"
Twitter is due to post its full year's earnings after the US markets close.
The loss-making firm's shares are trading about 69% lower than where they were a year ago, partly because of concerns that its number of users is not growing fast enough.
Last month the Recode news site reported that the service had cut the number of ads being shown to some of its most active users as part of an effort to keep them engaged.
More recently, the hashtag #RIPTwitter began trending on the service after Buzzfeed reported that the platform planned to change the order tweets were presented in.
The firm has since clarified that a toggle switch in its app's settings will allow the new function to be turned on and off.
If left selected, the "never miss important tweets" setting will affect up to the first 60 tweets shown at the top of a timeline.
If the user pulls to refresh the feed, it will return to its normal reverse-chronological ordered state.
Twitter said that users would see an on-screen prompt to alert them to the feature the first time they encountered it.
"No matter how much time you spend on Twitter, you probably feel like you've missed important tweets from accounts you follow," it said.
"We hear this from people every day. As a content consumer, the new Home timeline feature will help you catch up on tweets you don't want to miss from the people and topics you care about.
"As a content creator, it means your followers are more likely to see and engage with your best tweets. We've already noticed that people who have used this new feature tend to retweet and tweet more."
The firm's chief executive Jack Dorsey is expected to be quizzed about the expected impact of both the new changes during a conference call with analysts following its earnings announcement.