SEATTLE — Amazon.com Inc. said Tuesday that second-quarter earnings plunged nearly 58 percent as the online retailer focused on giving customers cheap or free shipping deals and investing in new technologies. Despite the hefty income drop, sales jumped 22 percent, which the company attributed to its focus on providing customers with things they want - such as the shipping deals. Amazon.com shares fell more than 12 percent in after-hours trading as the online retailer also said it planned to invest heavily in its new toy sales strategy and cut prices on many products. It also projected lower operating income for...