Because people who buy them never sit around watching silly ads.
Nine properties by the age of 29 - it is not a bad achievement.
I personally know people who were kicked out of year 8 ("for a good reason" they say) whose portfolio was substantially larger.
One comment I would take a liberty to make - it looks like the list of 11 tips (how to get started) was made shorter than it was originally. As always by removing useful advice.
Main piece that is missing "Find out how to borrow the deposit". Saving deposit is a waste of money. While you save, property becomes more expensive and you lose a lot of money as a result.