There’s been a lot of speculation about this for a while now and perhaps the question shouldn’t be – will they – but when will they? Now that Zynga.com are integrating Facebook ads onto their website, is this the first trickle before the sluice gates are finally opened to online publishers?

As Jon Mitchell puts it on the RWW

“Facebook knows who you are. Google knows what you’re looking for. Which piece of information is more valuable? The future of online advertising – and the ad-driven, free sites we use every day – hinges on the answer”

Could a Facebook ad network ever be a serious Adversary for Google’s AdSense network? Well, consider the spread of Social Media Widgets among these ad-driven, free sites we use every day.

From SEL: “Facebook Dominates Web With More Home Page Integration Than Google+, Twitter Combined. All Links from Top 10,000 Home Pages to Social Networks. Caveat: these are official widgets only.

• Facebook – 49.3 percent
• Twitter – 41.7 percent
• Google+ – 21.5 percent
• LinkedIn – 3.9 percent

As for the Mitchell statement, could be that – on most content driven websites -the potential knowledge garnered by Facebook will produce ads more pertinent to a visiting FB user than anything a Search Engine could ever come up with.

Re-targeting ads have already gone someway in combating banner blindness – but the FB ads could prove to be a real eye tug.