&gt; San Francisco-based Zynga is putting its San Francisco headquarters office property on the market for sale, according to sources that track the sale of office buildings in San Francisco.<p>They&#x27;re going to lose out on the fact that everyone stuck on 101 headed onto the Bay Bridge has to look at their billboard, sometimes for long periods of time. It&#x27;s definitely prime property that they&#x27;re giving up.