Well, this is novel. Husband-and-wife tennis pair Andre Agassi and Steffi Graf are amongst the “high-profile individuals” to have invested $15 million (£10.2 million) in secondary tickets marketplace Viagogo, after it already raised $25 million in 2006 and $30 million a year later. It’s now highly geared on $70 million venture funding.

Founded by US secondary ticketing agency StubHub‘s founder Eric Baker, Viagogo competes here with Seatwave and says this money will help it to become a market leader in Europe - even though it’s already based in Europe, London specifically.

Secondary ticket sites let ticket owners buy and sell tickets to concerts, sports matches etc - fine in theory, though tickets often end up priced radically over what they originally sold for (try £176 for a the upcoming Wales-England rugby game at the Millennium Stadium - a massive markup, and that’s the cheapest). MPs criticised such sites last year for supporting “bedroom touts”, but their ilk have escaped regulation and are now pitching clubs, theatres etc to strike more primary ticketing relationships.

Update: WSJ Digits: The new funding values Viagogo at more than $300 million, according an undisclosed source, this story says. Baker told VentureWire the new valuation is twice the amount given at the time of its previous funding round in 2007, but he declined to give a specific number.