Back when we spoke in person to staff in May, they were considering doing coin rewards besides just watching videos, such as a repeatable one time coin bonus to you for new readers who download the Tapas app using your referral code. They were also looking into bonuses for things like posting shares to FB and Twitter or reading so many pages.
This coin bonus for "headhunters" makes a lot of sense. It's expensive to advertise and word of mouth is the most effective way to get new customers anyhow. Most recognize that it's far more efficient to use your own customer base rather than trying to buy a base with hit-and-miss marketing. For example, Ibotta is offering $5 in cash referral for each new sign up, Swagbucks is doing $3 plus 10% of whatever the new person generates in revenue, for life.
Another option would be to add Peanut Lab Surveys to Tapas as another coin earning opportunity. Given that some very tiny websites (I know one with less than 5K monthly traffic) use Peanut Labs, it's probably fairly easy to integrate.
Now since the way to spend earned coins on non-premium series is finally available, staff will probably start the task of how to create more coin earning opportunities.