Stack Exchange sites that have graduated run so-called “Community Promotion Ads”: these run in the right sidebar of each page, and are designated according to votes on the Meta of each site. For example, see on Physics.SE how it works.
The good thing about these ads is that the new visitors they bring are, for the most part, already users on other Stack Exchange sites, and they now how the system works. Over at Chemistry, we have placed an ad on Physics.SE and it does bring us some traffic.
I’d like to propose that we come up with an ad to run on our sibling SE sites. I see three points to deal with:
- finding a nice motto or a catchy sentence
- creating the ad itself (having a nice graphics improves one’s click-through rate, but it's not absolutely necessary)
- coming up with a list of sites we want to target: I’m thinking Mathematics, Physics, Theoretical Computer Science, TeX - LaTeX, Mathematica, English L&U, Electrical Engineering (sorted roughly in decreasing order of suitability IMO)
What do you think?