Here’s what our default UTMs are:
utm_source=talkable
utm_medium={{ sharing_channel }} i.e. the channel that Friend came from originally, like email, facebook, twitter, and other (direct link)
utm_content={{ campaign_name | encode_query_argument }} i.e. the campaign name
utm_campaign={{ campaign_setup.id }} i.e. the campaign’s ID# (since campaign names can change or be cumbersome to read, the ID is short and sweet and will be unique for each campaign)