Perfect time to start laying out some groundwork.
It's somewhat like ignoring the teenager market.
For example:
Internet Users in US: 230,630,000 Population of US: 307,006,550 people
That's roughly 75% of the US population.
Internet Users in China: 298,000,000 people Population of China: 1,324,655,000
That's roughly 22.5% of the Chinese population.
However, by looking at the graph, we can also see that the growth of the Internet population is growing (exponentially) at a much faster rate in China than it ever did in the US.
I think we all remember when the US had far below 22.5%
You are absolutely correct. The goal of your investigation does in fact dictate if you should use percentages or absolute numbers. Likewise, 298 million Chinese Internet users is nothing to sneeze at!