Amongst the various announcements at yesterday’s Apple keynote, one perhaps didn’t get the attention it deserved, and that was the announcement Zynga’s wildly successful FarmVille game is to go mobile with the iPhone 4 being the first platform. But why is this so significant? Well, I can tell you that as a social media and digital communications specialist, people like me have been very interested in working with Zynga to tap into their huge user base.

Casual gaming has always been something that has attracted vast numbers of users, but brands have found it very hard to find relevant and sympathetic ways of engaging with these audiences and have often jarred with the culture of these games. FarmVille on the other hand has two major things going for it – first of, it was built as a Facebook application and it’s where is draws the majority of its user base from and second, it has a huge female user base.

Not so long ago, FarmVille opened up certain advertising elements within the Facebook application and later on the spin off site. But with the mobile device continuing to eat away at traditional desktop-based surfing, the potential advertising revenue starts to flow away to the mobile platforms as well. Which is why, just as OS 4.0 comes into being with the iAd platform, it’s an extremely smart move for the guys at Zynga and perhaps a move that will become much more significant over the coming months.