Hello Rikafip,
I think that
[ANN] Workbit - Freelance platform belong to be in the list of using bumping service.
Topic is self-moderated, lots of old Newbie and Jr.Member accounts that started to post on January 4-5. They post only in this exact topic and create a conversation between each other. I've made a simple post with hint that might help project to improve, but it seems on purpose it was either ignored or got no reaction.
You are absolutely right, they indeed hired bumping service and by the looks of it, they hired most popular one, Vitor Services. All accounts are at least few years, some are even from 2011 (I still wonder how they have so many accounts from that early bitcointalk period) and they are currently active only in Workbit announcement thread. Standard Vitor Services M.O.
Workbit thread has been added to the list, making it 90th entry since I started eight months ago, and that's just those were identified and reported here, who knows how many more are still undetected.