I have just come across a post an ZDNet about how advertising can affect open source. It claims that open source can be in danger if closed source comapnies start campaigns against them. It also raises the question how will open source projects defend themselves in the media.
But it does not say anything about open source projects that are backed by companies (such as Sense/Net). Companies like Sun or IBM, who spent millions on open source will not use their left hand to hit the right hand. They will defend open source as a movement, because for them it is an important marketing strategy.
So, I don't think ads are great danger to open source. Open source has long been useing social media anyway, and that is very strong. Do you beleive a Microsoft or IBM ad, or do you believe the insights of trustworthy blogers or experts in a forum? At first you see an ad, and than you check it in the social media, right? At least that is what I do.
And open source has another advantages, such as commitment of fans, and the source being open in itself. If companies start flaming the FOSS movement, open source enthusiasts will be even more enthusiastic.
We are a small business, and still we compete Microsoft and other big businesses. Most people think it is impossible, but as you can see from our references, large enterprises trust smaller It companies. Naturally, we won't kill Microsoft or sweep down IBM from the marketplace. This is not even our goal. The market is big, but open source will want to take its share in the future as well.