On Monday this week, the ASX-listed REA Group announced that its online business realestate.com.au was entering a series of "strategic investments in the mortgage broking market". In later news, it emerged that the deal included an agreement to acquire a majority stake in mortgage broking franchise business Smartline, as well as a strategic mortgage broking partnership with National Australia Bank.Smartline has over 300 advisers nationally, settling more than A$6 billion in loans annually, with a total loan book of approximately $25 billion. REA's realestate.com.au business will acquire an 80.3 per cent stake in Smartline, with the remaining 19.7per cent shareholding to be retained by the existing management team. This team will continue to be led by executive director and co-founder Chris Acret and will operate under its current structure and brand.The purchase consideration of $67 million will be funded from existing cash reserves, the company said in a media statement. The minority shareholders hold a put option to sell the remaining 19.7 per cent of shares which can only be exercised after three years, at a price dependent on the financial performance of Smartline. If the option for minority shareholders is not taken up, REA will acquire the remaining shares at the end of four years. The transaction is expected to complete in late July 2017.This deal further strengthens REA's move into financing, an integral part of property purchases. The benefits for other parties, notable Smartline, are less certain.ASIC also found that vertical integration through white labelling can raise a lender's market share. NAB and Advantedge's share of FAST, Choice and Plan loans was significantly higher than their overall market share (22.3 per cent compared to 13.2 per cent). NAB's share of FAST, Choice and Plan, however, was just 12.7 per cent without Advantedge.Just as interesting is the role of NAB. Vertical integration was covered by ASIC's Review of Mortgage Broker remuneration. Proposal 4 of that review recommended clearer disclosure of ownership structures - and realestate.com.au has been clear about NAB's involvement.NAB will not own realestate.com.au's home loan business but may be hoping that providing its white label products could have a similar effect as vertical integration.Also in question is whether other online property groups - specifically Fairfax-owned Domain.com.au - will now decide to enter broking, speculated The Adviser.REA said it expected its entire financial services segment to contribute revenue, net of broker commissions, of between $26 million to $30 million and EBITDA between $7 million to $11 million in FY18.