HomeAway upped the ante in its quest to transform its business, extending its new pay per booking business model to its VRBO.com site.

Under pay per booking, which is expected to get traction from professionally managed properties but is open to individual vacation rental owners, too, properties pay HomeAway 10% commission instead of the current model, which calls for annual subscription fees.

In other words, vacation rental owners and managers can list their properties for free, and only pay HomeAway when a guest books a property.

HomeAway launched pay per booking in October on HomeAway.com, has now extended it to VRBO, and plans on rolling it out to its global sites, which feature 773,000 paid listings in 171 countries.

A few HomeAway sites, including those in the newly acquired Stayz Group fold in Australia, already offer pay per booking.

HomeAway argues that pay per booking is attractive to owners seeking to list their properties for special events, such as the Super Bowl, because there are few up-front costs.

HomeAway also introduced its Professional Referral Network, which handles listings, inquiries and reservations for owners, to VRBO. HomeAway has 70 professional management companies that handle these services for owners.

Photo Credit: A vacation rental in Austin, Texas that was listed on HomeAway. Heather Cowper / Flickr.com