This British Airways promotional deal is valid for open jaw tickets booked travel period between 1st of November 2015 and 16th of December 2015 and from 7th of January till 22nd of March 2016. (except blackout period during Christmas holidays). This is based on date of your outbound flight to America. Max stay 3 months. Sweden or Copenhagen are connected with London by many low-cost airlines such as Ryanair or Norwegian. The quickest way how to compare your connection possibilities is through Skyscanner.
Before you book: Although the flights with British Airways are routed via London it is not possible to skip first leg Sweden-LHR otherwise your flight would be voided without reimbursement. On your return flight you may consider to end your journey in London and not continue to Copenhagen however we recommend this option only when you travel with no checked in luggage. (hand luggage only)
Booking samples
Sweden - San Francisco and Ontario (CA) to Copenhagen/Oslo (via London) for £244 (€331)
Sweden - San Francisco and Los Angeles - London for £286
Dublin - Los Angeles - London for £330
Sweden - San Francisco and Ontario (CA) - Germany for €329
Sweden - San Francisco and Los Angeles - Italy/Budapest/Warsaw from €388
Copenhagen - Los Angeles from €373/£275 (based on KLM, booking directly with airline, travel date sample 3. - 17.2.2016)
If you want to book your hotel room in America in advance you may check some affordable accommodation via booking agents such as Hotelopia. They are now also offering 6% promotional code for additional discount off hotel rooms. More details to be found here.
Booking sample with British Airways - cheap open jaw flights to California from €277/£201 here! In this case you would be departing from Goteborg to San Francisco on 13th of November and returning back from Ontario (CA) to Copenhagen (via London) on 29th of November 2015.