The company, previously known as BrainJuicer, had issued a trading update in April warning of the fall in gross profit – down 18% to £22.23m.

Its pre-tax profits fell 68% to £1.99m, compared with £6.28m the previous year – although the previous year are unaudited figures to allow for like-for-like comparisons following System1 changing its year-end last year.

While it described its financial performance as "disappointing" it pointed to its continued strong cash flow relative to profit and the board is issuing a final dividend of 6.4p per share (the same as last year).

John Kearon, CEO of System1, said: "We were slow to appreciate the speed and scale of change in our market, with painful consequences for investors and staff alike. The realisation that client budget-cuts were significant and probably permanent galvanised us to react, rethink and reinvent. 

"The result, we believe, is a more competitive and scalable offer, with the potential to build a much larger and more stable business over the years to come.  2018/19 will be a period of transition as we seek to sell-in our new and modified product offers against a challenging market backdrop."