I don't know. Sometimes my internet is really good. This afternoon, I could watch videos on youtube...with barely a pause. But now, it's not even working and I had to use a different internet source. The main problem for me isn't speed, but consistency. It's all over the place, and there's no telling when it will be good or bad. It was great all the time before Spring Break, and now it's not. I don't know what happened.

I'm thinking that like for many other things, there is a lack of regulation. While there are sites that are specifically slowed like Google, a slowness of the internet in general has to do with your internet source.

maybe it has something to do with all the filters 

I have a pet theory on that, but since I am not a computer nerd, I do not know if it will hold any water or not.  Maybe someone that knows more than me could come up with some reasonable explanation.

The Internet (at least for me with my provider) works very nicely and fast from about 6 am until about mid day.  From early afternoon onwards, it suffers a steady deterioration,and during evenings it is at its worse.  That is when I am "kicked" out, have "connection but no Internet access", movies are constantly stopped for buffering. sites are very slow to come up/

My explanation for this is that Chinese providers have lots of more customers than equipment to
adecuately give everyone a good reliable service, and during evenings, when everyone is connected and surfing, to prevent overloads that do selective disconects for about 20 minutes or so.

In my way of thinking, this is confirmed by my satellite dish.  Exactly the sme thing happens, I can see HBO, Cinemax, CNN,  BBC, etc very nicely, no interruptions during morning hours.

But some evenings, it will be a 5 to 10 seconds of movie and a 20 to 30 seconds of bufferning.  The satellite dish gets feed from two sources, the satellite itself and a connection to Internet.

So, give it a try and see if you can confirm my observations, please 

It's the way the ISPs here are set up.

In the US and other places, you have a direct line going into your home which is then connected to a small hub for the area.  That hub is connected to a larger hub, which is then connected to an Internet "backbone" hub - a huge routing server which directs traffic towards any location on te Internet.

"Internet" in China is nothing more than a huge Wide Area Network (WAN) that is connected to the Internet.  Technically, they could shut off access to the net, but you'd still be able to access sites within China (Taobao, etc.)  Now add on a ton of filters and "harmonizing" things coupled with the fact that you are actually sharing bandwidth with every person in your general area, it's a recipe for SLOW.

Case and point:  Ever notice how internet speeds slow to a crawl when it's raining?  More people are inside using the internet at that time.  Also in the afternoon - just check any office and you'll see most of the people chatting on QQ or watching movies.  They did most of their work (or just don't care) and are killing time before they can go home.  Like clockwork at one office I worked at, the internet would die about 3pm everyday.  In the office next to ours, that's when the boss would leave, so from 3-6 the employees there would just watch PPS or Funshion shows until they went home. 

So it's a combination of how it's set up, monitoring practices, and too many people using too small a system.