How do you make sure you get tickets through Ticketmaster?

i havent purchased new tickets in a while, its usually after market or free through work.

My wife wants to see Justin Timberlake in Fort Worth and today the general on sale began at 10am.

I logged in at 9:50 which was the earliest for the queue, and i was 2,400th in line. The venue seats 15k and the time it said i was ready at 10:01 it was already sold out.

What am I missing? How does anyone ever get tickets? Did they really sell that many presales, or are they bots and AI that brokers use?