Meta plans to add advertising to its social media platform, Threads.The initiative will be led by Meta's Instagram ad unit, with a small number of advertisers allowed to publish on Threads starting in January.Threads, a text-based social media platform built by Meta's Instagram team, gained over 175 million monthly active users in its first year.In an earnings report, Meta revealed its total advertising-related revenues of $39.9 billion in Q3, with ad impressions growing 7% year over year.