Land Rover recently became the first brand to execute a national Twitter campaign to promote its newest models’ debuts at the 2009 New York Auto Show.

The campaign promoted hashtag #LRNY in out-of-home venues like billboards and taxi TVs to spread the word of Land Rover’s Twitter efforts.

Was it a success? The campaign cost Land Rover nearly nothing and generated a significant increase in buzz leading up to the New York Auto Show.

According to a recent study, the best way to get Internet users to visit your website or follow your brand is brand mentions, not banner ads, pop-up ads, e-mail offers and sponsored links. So increased word-of-mouth chatter could be considered one form of success for Land Rover.

But what were people saying? Sentiment around Land Rover was largely positive during the spike in chatter, with words like “best” and “luxurious” appearing high in the results.

Digging a bit deeper, we wanted to identify the top influencers on Land Rover during the first few weeks in April. Using Social Radar, we created the visual ecosystem below showing some of the most influential sources and how they connected.

The visual is based on metrics such as the ratio of content matching the Land Rover query, post frequency, inbound link frequency, outbound link frequency, and more. For additional info, Social Radar users can click on any of the bubbles to see stats.

Nearly 45% of Internet users will visit a social network at least once per month, according to eMarketer, but social network advertising represents just 5% of overall online ad dollars. Should more companies follow Land Rover’s lead?

More importantly, can Land Rover use excitement around the campaign to sustain relationships with customers online?