Las Vegas - Mobile devices such as smartphones and tablets are changing the way consumers shop for their vehicles, making it critical for dealers to invest in mobile Web sites and mobile ads. That's the key message that was conveyed by Edmunds.com at the 15th Digital Dealer Conference & Exposition in Las Vegas, Nev.

Consider these statistics:

• There are an estimated 137.5 million smartphone users in the U.S. right now, and that number is expected to jump almost 40 percent by 2016.

• Today about 35 percent of Edmunds.com site traffic originates from mobile devices, up from about five percent of site traffic in 2010.

• A recent study found that mobile users are 88% more likely to do business with an auto dealer that has a mobile site.

"As mobile Internet usage grows, dealers who have embraced a mobile strategy are in a far better position to reach a customer who is ready to buy," said Kerri Wise, Edmunds.com's senior director of dealer training.