Marketing, obviously. They were technically correct, but the figures used were not "median income" (or whatever it is called).

TechCrunch has a table that shows the comparison between advertised and real earnings: https://techcrunch.com/2017/01/19/uber-settles-ftc-lawsuit-c...

Here's the actual FTC complaint: https://www.ftc.gov/system/files/documents/cases/1523082uber...

Seems to be a combination of overestimating the number of rides drivers could get, and underestimating the cost of vehicle ownership.

Does it matter? They're liars. Whatever justification they used for their lie is irrelevant.

edit: I thought I commented on this story topic before and found this from over two years ago

https://news.ycombinator.com/item?id=8523104

They probably faked the numbers to scam people into driving for them and entrench themselves in the market.

I wonder if those real numbers were based on a 40 hour week.