Nope, not allowed but yep, it happens constantly. Those members are obviously trying to disguise an advertisement as a genuine post, but IMO all of it qualifies as spam and should be reported. Did you report these posts? If not, please do so. Mods will probably delete the posts and perhaps nuke the members.
I've tried reporting and identifying paid thread bumpers for months but action is never taken.
There's at least 50 accounts connected with this service:
https://bitcointalk.org/index.php?topic=5160199.0I found about them because one of them was bumping the Bitconnect 2.0 thread, and others are bumping what is likely to be a scam project, Blue Hill Mining. There's several other illegitimate projects they are hired to bump.
As we all know competition for ANN threads is fierce, but at the same time we need to dissuade those who would be professional spammers. Its just a dishonest use of the forum.