A good point, but your reasoning is only valid if there is a correlation between posts and complaints, i.e. most posts are because of problems. I don't think this is the case.

A few examples:

1. doc: He posts the most and much of his content is informational/news-related.
2. UA BAHT pass: More than 600 posts about an opportunity, not a problem.
3. Promos: The more promos a brand has, the more topics and posts that will occur. Just from NW: Fly Free Faster and 200% partner mileage match.

While I agree that some posters get overly excited over small items (e.g., HHonors update bonus), I don't think that lots of posts within a forum indicate negativity toward that brand.

It's been mentioned in this thread that Starwood posters are very active. How much of the forum is negative? Sure there are some complaints, but many posters are simply telling others where to stay in a certain city - precisely the purpose of the forum.