Operating income at online giant Amazon jumped 89% to $4.4bn (£3.4bn) for the 13 weeks to March 31, as it plans to half delivery time for Prime customers.
Net sales increased by 17% to $59.7bn (£46.2bn) compared with the same period last year.
Amazon will spend $800m (£620m) in this quarter to half delivery speed for US Prime members, from two days to one. Prime customers are charged monthly and annual fees for delivery discounts and access to music and video content.
One day and same day delivery is already offered to UK Prime customers in eligible catchment areas.
During the quarter, Amazon announced plans to create 1,000 full-time apprenticeship roles in the UK over the next two years. The strategy will add over 27,500 permanent employees to the UK workforce.
In April, Amazon announced that it would be shutting its Chinese marketplace.
The online giant also launched Amazon Amplify - an initiative to increase the number of women in technology and innovation roles across its UK business.
Operating income is expected to be between $2.6 billion (£2bn) and $3.6 billion (2.8bn), for the second quarter of 2019.