There are some services offered outside the forum to shill the projects on the most active forum like this one. Sometime back we used to have a bumping service where people were hired to bump the ANN thread with some fake discussions. Though this act is a bit different as these accounts are not bumping any ANN but they are more involved in shilling the project while reply to the pots in different threads.
Yes, this is true. I have come into contact with such a project before, but that project has an ANN thread here on the forum. There was a project I was working on as part of their Telegram Moderators. One of their shilling tasks was for members to comment under their ANN thread, which was here on the forum. There were a lot of Spam posts under that thread; an account was being created just to serve that purpose, and it was really becoming spam. Last I checked the thread, a lot of the posts were already deleted by the moderator, I guess.
But there is one thing most shillers don't know about this pattern of shilling, and that thing is that the way a project is promoted says a lot about the project. If they are spamming the project around social media, the project might be seen as a scam. Too much of something turns out to be a scam just by looking at it. They might end up getting a scam tag instead of the attention they are looking for, unless they are just seeking clicks.