I'm not going to share my full traffic stats, but I will note that TDR's site traffic in May looks to be about 10% above April (not bad for this time of year on a tech blog). But what's even better is that my mobile traffic has grown as a percentage of the whole. iPhone traffic is up a tenth of a point over the past 2 plus weeks, and I'm also seeing slight gains in LG, Samsung, Ericson, and other branded smartphone browsers. That's good, but I've seen a very nice bump in traffic for Android.
Gadgets running on Android accounted for 7.3% of my traffic in April (same for previous months), while in May they account for 8.4%. That's an increase of over a percentage point in just over 2 weeks, and it's still growing.
I'll skip the math, but if the Android traffic continues to grow at this rate then I expect to see Android's share of my site's traffic grow at an increase of 2 percentage points each month (and that's not counting the boost from other mobile OSes). That alone should be enough to convince anyone of the value of adding a mobile site. And even if it tops out at 15% or even 10%, that's still going to be more traffic than I had before.
And all it cost me was a couple nights looking at plugins for sharing options and tweaking the layout - stuff I would have done anyway.