Web travel agent Expedia (EXPE - Get Report) is checking into the vacation home rental market with the $3.9 billion purchase of HomeAway (AWAY) . 

The deal comes as HomeAway is reworking its business model to resemble the more favorable economics of rival Airbnb, and the buyer suggested its experience with online booking would ease the transition.

HomeAway shareholders would receive $38.31 per share, with $10.15 in cash and the remainder in Expedia stock. Shares of HomeAway gained $7.77, or more than 24%, to $39.81 on Thursday morning. Expedia rose $4.90, or 3.65%, to $139.07.

While HomeAway has a network of 1.2 million whole-home rentals spanning 190 countries, the company's economics lag. The vacation house rental site generates about $500 million in sales from $15 billion in gross bookings, a take rate of about 3%. 

Cowen & Co. analyst Kevin Kopelman noted that Airbnb's rate is about 10% and that online hotel booking rates are typically above 15%, as stated in a recent report.

The company is shifting to online booking, an industry standard that should allow it to improve customers' experience. The move to online transactions will also enable the company to charge travelers a fee when they book trips. The new fees from renters will more than offset a planned reduction in fees that HomeAway charges renters.

Expedia's online properties include its namesake travel booking site, digital travel agencies Orbitz Worldwide and Travelocity, European hotel booking site Venere, hotel search firm Trivago and other properties. The buyer expects that its broad experience with Web transactions will help HomeAway make the transition to online booking. Expedia projects that it can increase HomeAway's roughly $120 million in Ebitda to $350 million by 2018.

Cowen & Co. analyst Kopelman wrote that Airbnb or Priceline  (PCLN) could launch a rival bid, but suggested that Expedia is the best fit. 

The buyer and seller already have commercial agreements, and Expedia is a more aggressive acquirer than Airbnb or Priceline.

Bellevue, Wash.-based Expedia has built its portfolio of travel sites through M&A. 

Deals this year include the $1.6 billion buyout of booking site Orbitz in September and the $280 million purchase of online travel agency Travelocity from Sabre  (SABR - Get Report) in January. HomeAway's bookings would boost Expedia's $23 billion in 2015 hotel bookings by 65%, Kopelman added. 

About $1 billion of the price is cash and the remainder in Expedia stock. Expedia said it will draw on cash already on its books and may raise funds in the debt market.

The deal requires approval from shareholders and regulators, and the parties expect to close in the first quarter of 2016.