Plus also there are some Internet Providers that Throttle their Bandwidth Speeds as well. When people purchase Internet Services they don't always get the Speed they are promised. When you look at most Internet Plans they advertise Speeds up to ****MBPS but it doesn't necessarily mean your getting the exact speed as purchased.
For example someone purchases Internet Service and was told they would get 100MBPS Service. If you look at the Service Providers Webpage it Advertises Speeds up to 100MBPS. It doesn't necessarily say you will get that exact speed. The Internet Provider could Throttle the Bandwidth and only give 20 or 30MBPS Service through Peak Hours of the Day most don't notice until they begin Streaming Video then they see a difference and figure it might be the Website they are viewing has issues when it could possibly be their Internet Provider Throttling Bandwidth. A verification on Speedtest.net will tell them the exact speed they are getting at the time when buffering issues occur.