Instagram opened its platform to most advertisers across the globe on Wednesday as the photo-sharing app seeks to make more money and compete with popular rivals such as Snapchat. Ads, previously available only in eight countries, will debut in more than 20 others including Italy, Spain and India, Instagram said. With 300 million monthly active users, Instagram has a key advantage over rivals because parent Facebook Inc’s vast trove of consumer data allows it to target audiences more accurately, a major selling point for advertisers.