I'm more interested in what goal does this campaign want to achieve?
If it is about spam, it would be enough to provide rules for example a minimum of 50 posts per week and a minimum of 20 characters in the post. That should be enough.
Now it's more like a challenge / competition than a promotional campaign.
seen someone in the meta section where he asked if he can do a signature campaign similar to what OP wants. its him actually lol its this thread
https://bitcointalk.org/index.php?topic=5229229.msg53931496this is the kind of campaign that intends to make a thread in bitcointalk to rank on some key words he wants. basically its for SEO and likely he wants links to its post as well.
Its best for OP to just hire someone to do a per post but he would have to be careful not to get caught else its a negative impact to his companies reputation.