42K a month? That's just crazy
I don't really remember how it works. But in case it was constantly scraping twitter to search for the POSH hashtag, would it bee been much cheaper to create a simple front-end where verified users can once a day submit the URL to a tweet?
This way you also promote quality over quantity on Twitter. I might be completely wrong about how it works of course.
I remember when the posh hashtag was going turbo mode on Twitter, the influx of new users on Hive was also great. It became even too spammy to my liking at some point, but my god was it effective.