After its latest funding round, the car booking app Uber is now said to be valued at USD 40 billion, making it worth more than Delta Airlines and Kraft Foods.  Tech expert Stuart Miles explains why Uber is attracting investors

Uber’s success with investors like Google Venture and Goldman Sachs is all about its very aggressive market strategy as well as all the attention the company is attracting, according to Stuart, who runs tech news site Pocket-lint.com.

Interest in Uber may also be fuelled by investors who failed to spot the opportunities in Twitter and Facebook and are keen not to miss the boat again, says Stuart.

The smartphone-driven taxi service has grown six times in a year, and is now operating in more than 250 cities in 50 countries. But with legal problems mounting in several US states and countries around the world, will Uber remaining exciting for investors or will it turn out to have been uber-rated?