And there are the thousands upon thousands of dollars that will come in from people who just want to try it out for fun, since it's only a dollar. Wicked smart.
Probably due to the novelty of this feature, income will spike and then fade away. Similar to any other startup article appearing on TC. This service will stop being used pretty fast.
The only way I see this service being successful going forward is by providing stats/analytics to users on post views, engagement, post virality, follower stats, etc. If this service is provided together with the $1 highlight feature, I do see a business going forward.