Community ads are a cool feature of Stack Exchange communities, but I have a feeling that in the last couple of years they've been somewhat nerfed, to the point that they're no longer worth it at all.
For the past few years, we've run the same ad on gaming, for the Child's Play charity. Here are the number of total hits per year for that ad:
2016: 1 (so far)
Maybe people are bored of this ad, and have stopped clicking it? No - none of the other ads on gaming have had any clicks at all (at time of posting - March 2016). If the current click-rate continues, we're aiming for a grand total of 6 ad clicks this year!
A quick glance at Stack Overflow's current ad stats shows that this phenomenon is not gaming-specific (remember that SO traffic outweighs gaming's by a large factor).
Are Community Ads being shown less often now? Is this a deliberate decision? If that's the case, it's really not worth the investment in creating them any more.