What are we measuring?
The average available internet speed is measured as the average of the maximum advertised commercial internet speeds available to households in each census block in the County.  The data on commercial internet availability come from the Federal Communications Commission (FCC), which requires internet providers to report advertised speeds delivered within each census block in the U.S.  Where multiple providers offer service, the highest speed was used to calculate the average for all census blocks, using the number of households in the block as a weighting factor.
Why is it important?
New technologies for business and the home continue to drive the need for ever faster internet speeds, or, more correctly, internet capacity.  Teleconferencing, cloud computing, high-definition video and virtual reality all require more capacity than more traditional applications.  The proliferation of internet-based devices also adds demand.  There is room for debate, however, over how much capacity is enough and whether the availability of very fast internet--for instance, in the gigabit range--is a significant factor in attracting businesses to an area.   
How are we doing?
As of December of 2016, Fulton County led all of its benchmark counties in terms of the maximum advertised internet speed when averaged over each census block.  Fulton's position was due primarily to one provider offering near-gigabit speed internet throughout much of the County.  This offering was accomplished not through the installation of a widespread fiber optic network, as was done in the places such as Chattanooga and Kansas City, but through the adoption new technology to increase the capacity of existing cable lines.