Real estate information provider RP Data yesterday announced a robust interim net profit, up 35 per cent to $4.7 million in the half year to December 2007, driven by a 49 per cent revenue increase to $21.8 million.The average number of monthly subscribers increased twelve per cent to 8675 for the six months to December 2007, with the average monthly spend up eleven per cent to $314.Growth in electronic valuation services includes five new finance companies, with valuation services now accounting for twelve per cent of revenue.RP Data highlighted a 15 per cent growth in electronic valuation services for the period, with chief executive officer Graham Mirabito expecting second half growth to be driven by acquisitions, mortgage refinancing activity and use of automated valuation methods."The major banks are buying AVMs hand over fist as a check valuation, as in rising and falling markets you need to collect as much information as you can."We have valuers using our AVMs as part of their reports just to show another independent source of data. We are seeing in a volatile market the use of data and analytics increasing."RP Data completed two acquisitions in the period.The firm confirmed the full year guidance previously announced, that year on year EBITDA will meet or exceed 25 per cent.