It's safe to say the typical acquisition made by a major company is meant to be synergistic. Most buyout targets are enterprises whose business roughly corresponds with, or complements, that of the acquirer.

And there are others where the compatibility isn't immediately obvious. In this category, we can slot online travel agency The Priceline Group's (BKNG 2.05%) purchase of AS Digital, a deal announced Sept. 3. Terms of the deal were not disclosed.

The company's new asset is seemingly obscure and off-core -- it's a restaurant reservation system provider based in Australia. Now, why would a travel powerhouse like Priceline want to own something like that?

Reserving potential
The immediate answer is that Priceline's already heavily involved in the online reservations business. In 2014, it splurged on the largest American reservations site, OpenTable. It coughed up a cool $2.5 billion in cash to buy the company, which it obviously coveted -- that amount represented a nearly 50% premium to OpenTable's stock price at the time.

Although the synergy isn't apparent at first glance, restaurant reservations and travel do go together. After all, tourists tend to be fairly free-spending souls and part of the magic of visiting another city/country is experiencing the local dining scene.

This sort of business, if OpenTable is any indication, is also very lucrative. In its last fiscal year prior to being swallowed by Priceline, the company netted $46 million in profit on $190 million in revenue, for a very wide profit margin of 24%.

Those kinds of results alone make it a good fit for Priceline, which collectively is a set of well-in-the-black travel(ish) assets. Lately, the company has been posting net margins approaching 30%.

Attractive Australia
AS Digital's geography also slots it in nicely with its new parent (and sibling; it will be fed into OpenTable's operations). That's because its home base is Australia, which provides a convenient springboard for Priceline's global ambitions for the U.S.-centric OpenTable.

Owning the company will, in Priceline's words, "serve to accelerate OpenTable's entry into the Australian market and expand its operations in Japan and across the Asia Pacific region."

That relatively fast-growing part of the world should provide a good platform for OpenTable to go international. The subsidiary needs to break out of America's borders. In its last reported quarter before the Priceline takeover, its international revenues comprised only 14% of its total top line.

Two-horse race
There's another dynamic at work, here, one that is almost certainly encouraging Priceline to keep its wallet open: consolidation.

Not long ago, the online travel agency space had four major players. Besides Priceline, these were Expedia, Orbitz Worldwide, andTravelocity.

But early this year, Expedia gobbled up Travelocity, and mere weeks later, struck a $1.6 billion deal to acquire Orbitz. So at the moment, the former quartet of big OTAs is now a trio, and looks set to become a duo if the latest proposed acquisition wins antitrust approval.

Both companies have been in an arms race for years, and that's only accelerated with the market's narrowing. In the wake of the EXPE/OWW deal, Priceline ponied up for travel rewards service Rocketmiles and a bigger stake in Chinese travel agency Ctrip.com International.

The road less traveled
Regardless of whether it's part of an overall rush to snap up assets or not, Priceline's AS Digital buy is a well-timed and opportunistic move (although we can't determine whether it was a bargain, as terms were not disclosed).

Restaurant reservations aren't a huge part of Priceline's business, but they're an indication of what might be in store for the company, such as slightly offbeat acquisitions that somehow complement its operations. AS Digital looks to be a good one. Investors will hope there are more like it.