Twitter said: "We partner with select advertisers and retweet offers that they have crafted only for the Twitter community. Our advertising partners determine the terms of the offer, including availability, amount, and price."
The new service, which will offer adverts from several of its exclusive partner brands, will appear on the web page like any other advert or tweet. Users can follow or un-follow @earlybird anytime.
Twitter has confirmed that @earlybird is a part of the company's efforts to monetise its services, but the company has not yet revealed on what terms advertisers will be paying.
Twitter has published a detailed report on the launch of @earlybird on the support page of its web site.