Honestly don't know enough about it to provide any authority....

Honestly don't know enough about it to provide any authority. Compression and encryption are very specific fields that I don't deal with on a regular basis. By virtue, SSL doesn't do HTTP compression because to do that you'd have to expose the data. That's not to say they don't have their own forms of compression, but it's just not as efficient. But I'm not at all an expert in this. Not even close.

One thing to remember is that not all data is the same. Video, for example, is widely different to, say, a text file or even code. That's because algorithms work on the premise that reduce memory by 'reusing' addresses that point to memory.

To those not at all savvy about this: it works like this -
Lets say that I build a restaurant that I go to when I'm hungry.
That restaurant I've built is located at address XYZ.

So now, next time I'm hungry, I don't need to build a new restaurant, I can just look at the address and go there instead.

Compression works kind of like that. It works by finding common patterns in the data, applying those to a set of addresses and then replaces that data with an address that says, 'Oh you want McDonalds? Go to XYZ'.