JLR's decision to build the new vehicle at Halewood will lead to the creation of 1,000 new jobs at the plant, which now employs 1,900 people, and has secured the site's long-term future.
The company says the car is the smallest and "greenest" 4x4 it has yet built and hopes it will prove popular with drivers who might not previously have considered a Range Rover.
The company used social media outlets and online marketing tools to promote the launch night and is now seeing the success of its strategy.
JLR says the video of the launch party that it posted online - and which was also shown on the Daily Post website - has been watched 1.8m times.
The launch event, hosted by DJ George Lamb, was also streamed live online.
On Twitter, "Range Rover" was one of the top ten most tweeted terms in Britain on the night of the launch and, during this period, around 6400 wall posts, comments, or "likes" were added to the Land Rover Facebook page. Meanwhile, Google returned over 400 articles from established news networks - including the Daily Post - and from more than 7,000 blogs.
Land Rover managing director Phil Popham said: "We're delighted we were able to bring the Range Rover Evoque preview party to such a large online audience.
"It's vital that we reach the right audience online, and this was a breakthrough way to reveal a breakthrough car.
"The statistics show the enormous interest there is in the new Evoque and Range Rover as a brand."
The strong interest is good news for Halewood, which shed workers as JLR battled the downturn in the car industry but is now gearing up for when the Evoque goes into full production.
Other celebrities at the Evoque launch included Zara Phillips, explorer Sir Ranulph Fiennes, Dragons Den star James Caan, Blur bassist Alex James and TV sports presenter Gabby Logan.
The party was held in association with fashion magazine Vogue - whose readership is one of JLR's key target audiences.
Land Rover design director Gerry McGovern said the vehicle, with its "distinctive falling roof and dramatic rising waistline", had been designed to win over new customers.
He said: "This car makes a powerful statement of the Range Rover's brand intent to appeal to a wider audience."
The Evoque now has its own dedicated microsite here.