Sedivy :
Speed isn't the most important factor when doing time sensitive stuff online. You want line quality. Something to test your ping, jitter, packet loss.
Try:
http://www.dslreports.com/tools (choose line quality-ping test or ping test-real time). Those test quality of lines for VoIP phones, which is about the same quality you want for skype/vent/TS/gaming.
True but downloading a youtube video is not time sensitive.
If a youtube video refuses to download then it isn't that his latency is bad it is that his bandwidth is low or that something is interfering with the connection causing either lower speeds or dropped packets.
The reason why the latency the site reported was low is due to the speedtest.net site picking a site much closer to your house than the other sites you are trying to access.
I get about 17ms latency to a local speedtest site, but i get about 40ms latency in wow server in Chicago about 900 miles away, versus maybe 90 miles for the speedtest site.
You getting a 13ms latency is a good sign.
What are your download and upload speeds that it showed and how much are you paying for.