Advertisers spent a record £3.98 billion on digital advertising in the first half of 2015 - up 13.4% year-on-year - according to the latest Internet Advertising Bureau UK Digital Adspend report, conducted by PwC.
Display advertising revenues grew at more than twice the overall digital rate (27.5%) to hit £1.31 billion - 33% of total digital adspend, its largest-ever share.
Within display, video adspend grew 56% to £292 million (22% share); social media spend rose 51% to £574 million; native/content grew 50% to £325 million (25% share); and tablet-dedicated adspend grew 115% to £68 million.
"Recently, a lot of the attention on digital advertising has been around the challenges, such as ad blocking," said Tim Elkington, chief strategy officer, IAB UK.
"However, it's clear to see the UK digital advertising industry is maintaining its strong revenue growth at a much greater rate than the overall economy. The fact remains, as consumers spend more time on connected devices, advertisers must increasingly direct their attention and budgets there."
Adspend on mobile increased 51% to £1.08 billion in the first half of 2015, making up 79% of the rise in overall digital ad revenues.
Over a quarter (27%) of all digital advertising spend now comes from mobile, compared to 20% a year earlier.
Mobile currently accounts for 39% of display spend, 43% of video spend, 63% of social media spend and 74% of native/content spend.
Dan Bunyan, senior manager at PwC, said that mobile is "unquestionably the engine of digital growth."
"However, there's plenty of room to grow, as mobile accounts for 40% of internet time but only 27% of adspend," he added. "Marketers are realising this is out-of-kilter, hence mobile is likely to continue gaining share at pace."