The campaign is called "know how", and aims to position the bbc.co.uk website as the most reliable alternative for finding information if a trusted source, such as a friend or family member, cannot answer a query.
The push was created by BBC Broadcast and uses the strapline: "If your usual source of information lets you down, use the next best thing." It focuses on the various lifestyle pages of the website, such as food, DIY and parenting.
Executions include 30- and 40-second television commercials, two types of outdoor posters and up to four radio spots.
One television spot features a girl cooking and asking her mother for advice by phone. Her mother - viewed via a split screen - is comically knocked unconscious by a light fitting, leaving the girl to turn to the BBCi website for answers.
Posters will run in more than 1,000 outdoor locations, the first time BBCi has used a non-BBC media platform to advertise.
The ads feature a red mullet to promote the online availability of food preparation information, and a pregnant woman to promote the child-care information that appears on the website.
The campaign was art directed by Anton Ezer and written by Ben Friend.
The television spots were directed by Spectre's Rory Rooney as part of a BBC Broadcast team.