Normally when you get a red message, it's because someone has posted a spam message advertising something (not always that relevant or interesting to you, as you've already seen!)
We don't let anyone advertise or promote products on the forums, otherwise it gets mixed up with genuine product recommendations from gransnetters, which then seem less trustworthy by comparison.
The reason that deleted threads stay on Active, Last Day etc is because the system needs to 'refresh' itself before working out that the discussion has gone. <looks knowledgeable about tech thingummies that really are way over my head>
Hope that helps
