Online property group Zoopla reported record revenue in the first half as audience numbers grew.Total revenue for the six months ended 31 March increased 10% to £42m, as average revenue per advertiser (APRA) rose 13% to £340 despite 16% less customers. The group said while UK agency churn has slowed significantly, it is moving back towards normal historical levels.The number of visits gained 11% to 265.5m, driven by mobile devices which accounted for 60%, up 34% year-on-year."We have also reached a significant milestone of over 6m app downloads as consumers continue to choose our websites and mobile apps as their primary resource when researching the property market and looking for their next home," said chief executive and founder Alex Chesterman.Adjusted earnings before interest, tax, depreciation and amortisation (EBITDA) climbed 14% to £21.4m.The company said it has been trading in line with management expectations and is well positioned for long-term growth.In April, Zoopla announced the proposed acquisition of UK price comparison website uSwitch for a total consideration of £160m. The group is holding a general meeting later on Wednesday to seek shareholder approval. Financial Conduct Authority approval is also required, which is expected to be received in June."The acquisition of uSwitch is a significant step in the group's mission to be the most useful resource for consumers and the most effective marketing partner for professionals across the property space," Zoopla said.