The US is now the biggest market for online market research specialist YouGov following recent acquisitions, and contributed towards a surge in profitability last year.Adjusted profit before tax in the year to July 31st rose 43% to £5.8m from £4.0m the year before on revenue that jumped 26.9% to £56.1m from £44.2m the previous year. Market expectations had been for profit before tax of £5.26m on revenue of £55.04m.Reported profit before tax, which includes one-off items such as impairment of goodwill, amortisation of intangibles and other exceptional costs, weighed in at £0.48m, versus a loss last year of £10.58m.Adjusted operating profit climbed 39.5% to £5.3m from £3.8m the year before, with the adjusted operating profit margin rising to 9.4% from 8.5% last year.Adjusted earnings per share soared 88% from 2.5p last year to 4.7p, well ahead of the 4.12p the market was expecting."This performance reflects organic growth in the business as we develop new products and serve new clients as well as our successful acquisitions in the US, which are delivering ahead of expectations," said YouGov's chief executive, Stephan Shakespeare.Organic revenue growth (excluding the effect of acquisitions and disposals) of 9% was well ahead of the research market, particularly in the UK and US, the group noted."The core model is working well across both the existing and acquired businesses as we explore new opportunities for continued growth," Shakespeare added.Current trading is in line with market expectations.The group ended the year with net cash balances of £9.4m, down from £15.6m a year earlier, but the group did splash out £8.1m on acquisitions during the year.Despite the cash pile, there is still no sign of a dividend, but the board said the no-dividends policy remains under review. --jh