Why does it matter if someone gets a free plug? PPRUNE is not the BBC, which is publicly funded by the license fee and therefore has to be even handed. If someone is good enough to get a personal recommendation by a punter (PPRUNer?) then so be it! I see no scope for the competitor who did not rate a mention to sue PPRUNE for being unfair, and anyway the remedy is simple: they can sign up and post there own URL. I just don't see the risks here.