Smaato has released details of clickthrough rates (CTR) and ad network fill rates for the global mobile advertising market for June. The figures show further significant increases by Android in global CTR, while leaders Symbian and feature phones both suffer a dip. Smaato serves over 8m ad requests in its network of more than 6,000 registered mobile publishers and over 40 mobile ad networks.

In the US, while Symbian still dominates in terms of CTR, and despite enjoying only a small market share, Android has closed the gap with a CTR Index of 192 compared to 118 in May (average is 100),  while Apple iOS drops down to fifth place in the US, with a CTR Index of 73.

At a global level, Symbian leads the way with a CTR Index of 144 (159 in May), with feature phones in second place on 135 (147 in May). Android made the largest gains in the CTR Index in June, climbing above Apple to third place with a CTR Index of 58, compared to 40 in May. 

Smaato’s stats also measure the fill rate of mobile ad networks, which is defined as the percentage of ads delivered per ad request, and varies by different factors, such as country, device and content type. The individual ad networks are not published in the Smaato metrics, but are revealed in the dashboard of registered Smaato publishers’ reporting and analytics tools.

After three months in decline, the fill rates of the global top 10 ad networks have recovered slightly, climbing to an average of 22 per cent. In June, however, there were only four ad networks performing above this average. The top performing ad network lost 40 percentage points in comparison to May, and in June only had a fill rate of 56 per cent.

Finally, Smaato looked at ad network response time worldwide. The fastest response time in June was measured at 27 milliseconds (ms), an improvement on the fastest time of 39ms in May. The fastest responding ad network is more than twice as fast as the second quickest, which came in at 66ms. Smaato says that publishers should consider response times when adding several ad networks within a page load. If an ad is requested from a mobile ad network and no ad is available, then a faster response time enables the request to be sent to one or more other networks for a chance to get an ad delivered.

You can see more stats and charts here. And you can join the Smaato ad network here.