This is a follow up of this question after I found out that there is free vote-based advertising for Open Source projects.
I was told that logos could be added to tags whenever somebody paid for it. Now I don't see that very likely to happen for big open-source projects like R. I do understand that SO need some income, but I guess that those logos on tags aren't the biggest income as yet.
Therefor I'd like to propose to add the logos to the tags of open source projects like R, at least until some company decides to pay to add their own logo.