this maybe a dumb question.. why is the Mega hosted file 6.8Gig and the GoFile file 7.1Gig? something to do with compression?
Not dumb. They are the same size, they are just calculated differently.
As you know, the "giga" and so forth refers to steps of 1000, so a gigabyte is 1000 megabyte, 1 million kilobyte, 1 billion byte.
However, computers work with powers of 2, and since 1024, which is 2^10, is conveniently close to this step of 1000, some prefer using steps of 1024. They are usually called "kibibyte", "mibibyte", "gibibyte" to differentiate them from the others, and they should not be marked GB but GiB, but sometimes that is forgotten and even if not easily missable.
So here one gibibyte is 1024 mibibyte which is 1024*1024 kibibyte and 1024*1024*1024 byte. And suddenly you have 1 gibibyte as around 1.07 gigabyte. It does not calculate exactly here, probably because of rounding, but a roughly 7% difference in display happens for that reason.
But as said, they should be the exactly same size, just shown differently.