However, when Serena then later asked for tickets to see the likes of Andy Murray in action, she was shocked when the organisers asked her to stump up $100 for each ticket.
So what do modern, internet savvy people do when somebody or something irks them? They tweet of course - and Serena told her legions of followers to boycott the event in LA after the PR own-goal from the organisers.
You can see her tweets in full in the picture below, but for those who are not fluent in text speak the basic translation is this (we think):
"Oh my god, the Farmers Classic tournament in LA is charging me $100 a ticket after I did publicity for them. (Laughs out loud) I'll send them a bill for my publicity.
"Anyway, don't go if you're in LA. I would have paid $1,000 if I had not done publicity for them."
Serena then "re-tweeted" a tweet from one of her followers, benthomas10009, who said: "That is awful, the greatest women's tennis player ever has to pay to see a tennis match...disgusting."