Today, American Express announced a service that will allow its members to make purchases on Twitter using only #hashtags. Consumers are used to one-click shopping on Amazon. But what about one-tweet shopping on Twitter? That's the promise of a new partnership between American Express and Twitter. Today, the credit-card company announced a service that will allow its members to make purchases on Twitter using only #hashtags. It's part of AmEx's strategy to tap into the growing social e-commerce world--to show that social media can actually have an ROI beyond ephemeral buzz and memes. "Our ... Read More