Running a speedtest and reporting the results is akin to running a ApacheBench on your index.html, recording how fast it goes, then telling everyone your PHP server can serve pages that fast.
Speedtest by default finds a local server, which is almost always delivered over local uncontended peering. Of course you're going to see great results, you might as well be testing to a Speedtest server plugged into your LAN.
Run speedtests to ~10 sites around the country and a few around the globe and report those figures.
People want to measure the bottlenecks they can control. Speedtest shows what speed your first few hops get. In most cases, "The Internet" is much faster than their DSL line. In this case, that's not true, but there's not much that can be done by the end user.
Running a speedtest and reporting the results is akin to running a ApacheBench on your index.html, recording how fast it goes, then telling everyone your PHP server can serve pages that fast.
Speedtest by default finds a local server, which is almost always delivered over local uncontended peering. Of course you're going to see great results, you might as well be testing to a Speedtest server plugged into your LAN.
Run speedtests to ~10 sites around the country and a few around the globe and report those figures.