Online marketplaces, also known as platform companies, are sprouting up everywhere and redefining business in every industry. “The Uber of ….” has become shorthand for tech startups looking to redefine the way everything is delivered, from legal services (Sydney-based LawPath) to Package deliveries (San Francisco-based Doorman), to Lottery services (Gibraltar-based Lottoland).

Paris-based Videdressing offers global aftermarket luxury branded fashion and Los Angeles-based DogVacay is an Airbnb-style online marketplace for dog vacations that has created a network of more than 20,000 pet sitters. It has raised more than US$45 million from investors.

Major online marketplaces are attracting the attention of leading technology investors. Last year Sydney-based Expert360, the global marketplace for consulting talent, attracted A$4 million; Artsy - the NY based global marketplace for artwork - closed US$25 million, and Shyp the San Franscisco based on-demand shipping services marketplace finalised another $US50 million in investment.

There are currently 5,723 early stage private online marketplace companies listed on AngelList the leading online marketplace for investors in early stage technology startups. The average valuation is US$4.5 million - so that is about US$25 billion worth of early stage startups in this area.