Hard to believe people will waste at least six minutes of their time for a mere ten cents

. Yet another reason why there should be some restrictions on brand new accounts.
I dont think shadow banning newbies will be very effective in combating this. Users will not necessarily use low level accounts to make these kinds of posts. I have previously suggested that Ann threads with a post within xx time be displayed in a random order, which would effectively make bumping more than once per day pointless.
The ones who are only hearing about bitcointalk through that listing will be using brand new accounts. None of them are going to buy an account to do so. At ten cents per post it's probably only brand new desperados that are even going to bother with it.
but it doesn't rule out the possibility that it could be initiated by the ANN owner itself
need some solid proofs and probably quite hard to find in this case
Not very hard, staff here can contact the webmaster of that micro jobs site and then ask the details of the person posting this job . Then it can be matched with the ANN owner and this can be confirmed. It will take few minutes and help us get rid of a scammer here.
Why don't you waste your time doing that and see how helpful it is. I doubt they'll even reply and the info probably wouldn't be relevant or helpful. All they'll be able to give you at most is the email address or IP they signed up with and I dount they'll have used one that can be tied directly back to their ICO.