Let us examine a case of how a simple chart with few colors can give instant insight into the underlying data.
Here is the plain old table of data from City of Chicago
Let us see how we can analyze it in different ways.
This simple line chart shows the growth of Library WiFi usage in 2013 compared to previous years. Notice the dip in 2013 during August timeframe.
Same data but different chart
So which chart does a better justice?
And here is how the original data looks like
Finally, here is one extravagant option.