The phrase "publicity coup" refers to a clever and successful move or event that gains a lot of positive attention and publicity, helping someone or something become more popular or well-known. Full definition
«Tories in Buckingham will be free to vote for Nigel Farage but CCHQ worries about publicity coup for UKIP Main A Conservative Government would prioritise tackling the excesses of public sector pensions» (conservativehome.blogs.com)
Hardy also scored a publicity coup with Daly, who made Mystic Rock his first public appearance since completing alcohol rehabilitation. (si.com)
He has warned that losing the vote would be a massive «publicity coup» for the terrorists. (buzzfeed.com)