Mobile phone shopping is easier than driving to the store or even booting up a laptop to make a purchase because you can do it when you’re inspired to make a gift purchase. Maybe that’s why eBay performed remarkably well this holiday season. The e-commerce auction and retail company says that users purchased 1.5 million eBay items from either eBay’s mobile site or their iPhone app over the holidays.

According to eBay, purchases ranged from the mundane to a $75,000 1966 Chevrolet Corvette, a $19,000 boat, and a $10,000 Steinway grand piano. Overall, eBay says the site’s mobile transactions added up to half a billion dollars in 2009. The iPhone app has been downloaded nearly 6 million times, while the mobile site gets 750,000 unique visits per day.

The iPhone app is available in eight languages and is downloadable in 77 countries; it is the third most popular app in the iPhone Lifestyle category. In 2009, eBay integrated PayPal into the eBay mobile Web site and iPhone application. Today, every two seconds an item is purchased using eBay mobile.

“Mobile is changing the way people shop,” said Lorrie Norrington, president of eBay marketplaces in a release. “eBay buyers and sellers have rapidly embraced mobile commerce this year, and this holiday season has been a mobile commerce tipping point.”

As more shoppers turn to their mobile phones to make purchases, mobile marketers have the opportunity to make direct sales, instead of having to prove ROI based on unclear metrics. Both sides of mobile marketing will remain valid, but direct sales give mobile marketers the opportunity to prove even further value, and grow their businesses.