Samsung Electronics Co said on Tuesday its Galaxy Gear has become the world's most popular smartwatch with sales reaching 800,000 since its debut two months ago, defying some market concerns the accessory would fail due to a lack of compelling features. The South Korean firm said Gear sales have been better than its own expectations and it would expand sales promotions for the wearable device for the crucial year-end holiday sales. Samsung has poured marketing resources into the Gear with heavy advertisements and collaborations with fashion shows to seize leadership in the wearable computer market after the device got off to a rocky start after being critically panned by reviewers. The product marks Samsung's latest attempt to prove that it is more than just a fast follower in innovation behind Apple Inc. The Cupertino California-based firm is widely speculated by media and analysts to be working on wearable device.