I recently enquired about advertising my StackExchange site on specific tags on SuperUser. I was informed that tag-targeted ads are only supported on StackOverflow.
There are a small set of around 20 tags on SuperUser that overlap with my site, ideally I'd like to target these tags to maximise my limited advertising budget.
Is this limitation a technical or financial decision? Will it be possible to target tags on SuperUser if/when it reaches a high enough volume?