Last-minute accommodation booking service HotelTonight is about to embark on its first international expansion, adding a London office for a push into Europe, and launching in Toronto and Vancouver. The super-slick app has been exclusive to the US since its founding in 2010.

HotelTonight CEO Sam Shank tells us that the company will also be launching an currency conversion tool with version 2.0 of its iOS apps, allowing travellers to convert Euros and pounds, as well as US and Canadian dollars.

HotelTonight has also partnered with Los Angeles startup Look.io, which offers a real-time support plug-in, to improve customer service within the app. Using Look.io, HotelTonight’s team can chat with customers in real-time directly from the support screen. Shank says the feature, which is baked into the app, is the realization of the company’s efforts to fully embrace its mobile-only approach to hotel booking.

Another key aspect of HotelTonight’s new support system is its screen-sharing capability. Once a session is approved by both parties, a small cursor representing the support staff’s on-screen position appears in the middle of the user’s iPhone screen.

Screen sharing follows a “show, don’t touch” approach: While the cursor can move around the screen and is capable of emulating a variety of actions, it doesn’t perform any actions. It just demonstrates what users should do.

Look.io’s integration will only be available on the iPhone at launch, but Shank said that the plan is to bring the feature to other platforms – particularly the iPad – once the team believes the technology is ready to ship.

HotelTonight’s aggressive expansion comes relatively early in the app’s lifetime, and the move is designed to stop European competitors from sewing up large chunks of the market. Such an aggressive play, however, can cripple startups if they don’t bide their time and make sure all of the paperwork is in order. One need look no further than Turntable.fm‘s rapid international launch and subsequent withdrawal for an example of how important working within the system can be.

Ultimately, HotelTonight’s success hinges upon more than just securing the best deals or gaining the most customers in a given market – though that certainly helps. HotelTonight is successful because of the way that it has capitalized on two trends: Going mobile-native and personally curating the hotels that the company is willing to partner with.

Vice President at Accel Partners Max Neiderhofer, who helped facilitate the startup’s London move, sums up HotelTonight’s key strength as being “a mobile-native application in the sense that it enables you to do something that you weren’t able to do before.”

His care to say mobile-native instead of mobile-first speaks to a rising trend in Silicon Valley in which companies focus on providing the best-possible mobile experience instead of providing a half-assed application and hoping that it works “well enough.”

Neiderhofer also says there is huge benefit to having humans curate content instead of relying on computers. Internet-based recommendations have evolved past the point where an automated matching system sufficed.

“Now we’ve gotten to the point where all these hacks are nice,” says Neiderhofer, “but what’s truly valuable is an editor going through and saying that this is the best pick and then surrounding this with what we know about you and what other people have said about the experience.”

A recent story in the New York Times highlighted the surprise return of human travel agents in an age when online booking can be as cumbersome as the old analogue way of booking travel. HotelTonight, with its middle-ground offering that mixes human selection and customer support with automated booking in the convenience of an app, is a leading example of how a new ecommerce paradigm might look.

Now just keep an eye out for how TripAdvisor responds.

[Illustration by the amazing Hallie Bateman, who has a lot more art on her website, as well as a Twitter.]