Private accommodation will account for almost a fifth of global hospitality bookings within two years – and the online travel agency giants are tipped to benefit.

In terms of figures, financial analyst Susquehanna International Group (SIG) says private (alternative) accommodation is expected to hit $106 billion in 2018, some 19% of the overall pie of global room bookings in the market of $555 billion.

The overall share of private accommodation is increasing steadily, but not as dramatically as some might have guessed, with its portion of the market in 2014 at 16% ($69 billion) and 2016 at 18% ($88 billion).

Sector posterchild Airbnb is inevitably considered the dominant player in the market, yet it is the efforts of the Priceline Group and Expedia Inc that is capturing the interest of the money folk.

SIG says the pair (through their respective Booking.com and HomeAway brands) are well-positioned to benefit on the growth forecast in private accommodation – essentially meaning they have both sides of the hospitality equation in their grip.

Expedia Inc, SIG says, will see the advantages of cross-marketing HomeAway’s inventory around the group of brands (Expedia, Hotels.com, Venere et al), as well as gradually doing away with the subscription-based fee for suppliers towards a transactions-based model.

This also includes eventually ensuring all content from the HomeAway portfolio is instantly bookable online – a process at HomeAway that has previously been considered as disadvantageous in the battle against other intermediaries.

Over at Booking.com, SIG says its strategy of aggregating supply in the same way it has with hotel properties (instantly bookable) will allow it to “capture meaningful market share” in the coming years.

The group’s position with not charging a booking fee to consumers is also considered a plus point against the likes of Airbnb and Expedia.

Both groups are tipped to accelerate their respective shares of the private accommodation market over the course of the next two years, with 18% for Expedia Inc and 11% for the Priceline Group.