Speaking at an Association of Online Publishers (AOP) event on managing change in digital businesses, Christie said development costs for FT.com's recently launched iPhone app and the 'click and save' feature on article pages had been recouped largely from advertising revenue around the products.
The FT's iPhone app, which went live in July, was launched with Siemens as a sponsor and offered a subscription package for users wanting specialist news and information.
Further advertising on the iPhone app and paper's mobile site is selective, because of a lack of space and to meet the demands of iPhone users, who are very particular about advertising, FT head of mobile, Stephen Pinches, told Journalism.co.uk at the launch.
Other new innovations for the website, such as Lexicon, a new glossary of financial terms, launched this week, are also likely to cover their own costs, Christie said.
Earlier this week the site launched a new online community and news section, the Trading Room, while last October it launched a free-to-access members club, the Long Room, with plans for targeted advertising.
"These are quick and simple innovations. Our commercial team and our editorial team live and breathe innovation - that's the attitude we take," she told delegates.
But she said the core of the site and the FT as a title had also undergone massive changes as part of a move to become a digital business.
Earlier this year the FT announced the next phase in changes for its editorial and production staff, including plans for all FT stories to be filed and edited within the web channel of the editorial content-management system (CMS), Methode, by reporters, writers and sub-editors.
In addition, its pioneering registration and subscription model, for example, had been introduced and developed after consulting all stakeholders in the site, from the commercial and subscriptions teams to editorial, she said.
"We would be in deep financial straits without this model working today," she added.