Google and Facebook will continue to dominate the digital advertising landscape in the UK for at least the next several years, according to eMarketer’s latest forecast of UK digital ad spending. The two tech companies combined will reap more than half (54%) of all UK digital ad revenues this year, totaling £6.30 billion ($8.50 billion).

Google will remain the UK’s largest advertising destination: In 2017, the search giant’s total UK digital ad revenues will amount to £4.43 billion ($5.98 billion)—38.8% of overall UK digital ad spend this year—and rise to £5.10 billion ($6.88 billion) by 2019.

Facebook is expected to reap £1.87 billion ($2.52 billion) in digital ad revenues in the UK this year. Thanks to the success of Instagram as well as further investment in video, additional revenue growth is predicted through 2019. By that time, Facebook will take an 18.3% share of the UK’s digital ad market, amounting to £2.57 billion ($3.47 billion) in revenues, eMarketer estimates.

eMarketer predicts UK digital ad spending in total will reach £11.44 billion ($15.44 billion) in 2017, up 11.0% from 2016. Mobile continues to drive growth in digital ad investment, with mobile outlays predicted to rise another 27.4% this year and be responsible for 36.6% of total UK digital ad spending. Within mobile, video will see the greatest growth, increasing 47.7%.

Traditional media ad spend remains relatively flat in the UK, with some declines suggesting that marketers have been dedicating larger sums to support digital activity.

“There have been signs of tough times ahead for the UK ad industry,” eMarketer senior analyst Bill Fisher said. “Despite uncertainty around Brexit and struggles among some of the big agencies, digital continues to attract ad spending, with Google and Facebook the biggest beneficiaries. That they’re attracting such spend is perhaps a symptom of the wider market concerns, with brands looking to get the biggest reach for their buck—something that Google and Facebook clearly offer.”