426 billion tweets, dating back to the very first one in 2006. The entire history of Twitter – as well as tools to analyze in real-time tweets’ influence, relevance, sentiment and geo-inference —  are to be contained in Topsy’s social data index as of 11 AM EST  today. It’s available to users both of its free social search service and its Topsy Pro Analytics offering. The feature, known as AllTweets, also is to be available in all of its API offerings that developers use to access information programmatically in order to make any application social.

“The key here is instantaneous validation of information,” says Jamie de Guerre, Topsy’s SVP product and marketing. “Our deep expertise and data infrastructure can provide instant insights across 425 billion tweets at scale like no other analytics provider can do.”

It can make for a fun tour back in time for the average consumer, giving him or her a look at the first tweets from any handle, or a particular handle’s most trafficked tweets, for instance. (Check out Twitter founder Jack Dorsey’s first tweets, if you like, in the screen shot.) Previously, Topsy let users access a full index of all tweets and referenced web content from 2010 through today.

But why would a brand’s marketing staff or other professional users need to go back in the past – whether that’s seven months or seven years ago? “In the majority of use cases of Topsy Pro, there is a lot of analyzing around what is happening right now and in real time,” de Guerre confirms. “Unanticipated things come up and being able to instantly analyze those is a key advantage that Topsy has that is important to all marketing customers. But when you want historical data, that tends to be for benchmarking something that’s happening now against something that happened in the past.”

Doing so, he says, can help a brand or other parties – hedge fund investors, for instance – determine whether they might really have something to worry about, or whether there’s an opportunity just waiting to be harnessed. For instance, with new Apple iPhones set to be launched next week, it might be a good time for investors to explore what happened at the iPhone 4s launch between its announcement last Oct. 4 and the reveal of initial sales results Oct. 17. de Guerre notes that at launch time, the press was harder on Apple because the iPhone didn’t break expected ground in features like form factor. But Topsy Pro’s Twitter insights showed that, starting a couple of days post-launch, sentiment around the new phone was overwhelmingly positive.

“There was a good ten-day period where you see positive sentiment in Twitter through our analytics, indicating it will be successful when all the press had been more negative,” he says. Past information like that could prove valuable for the upcoming launch, he says: “This time, when the iPhone 5C and 5S gets launched next week, if the press is negative again but sentiment in Topsy is positive again, investors may say that they are going to buy Apple stock, because it’s happened before and in the end the 4S was a huge success.”

As an example of using past data to plan a marketing response to an unexpected event, de Guerre mentions that a beverage vendor may have wanted to compare the Twitter-sphere reactions around #therealbears, “The Unhappy Truth About Soda” campaign launched last October to alert users to the obesity dangers of sugary drinks, to those that surrounded New York City Mayor Michael Bloomberg’s proposal to ban large sugary drink sales in the summer of 2012 and the NYC Board of Health’s approval of the idea last September – only to be followed by the ban’s being struck down by a New York Appellate Court this past summer.

A soda vendor couldn’t have anticipated the launch of #therealbears effort, he says, and when it happened it made sense that it would want to analyze who were the influencers driving the Twitter conversation and what was the top content. But was this a major crisis that needed a full-court press response? ”The next question [the soda vendor] would have is how to benchmark this against something that happened in the past to see if they need to activate this issue, do they need to plan a response and how significant should it be. This is where a historical data set can become valuable,” de Guerre says. Turns out that while there was a huge spike in conversation for #therealbears at launch, the NYC soda ban’s news got a lot more Twitter traction, information that could help a beverage vendor decide it didn’t need to throw a huge amount of marketing attention and resources behind the issue.

Says de Guerre, “We now will now have over 425 billion tweets, vides, images and any other linked content available through the instant live index – and that makes it a larger social index than either Bing or Google provide. It’s more tweets and web content than we believe Bing has in its index of web pages. That’s important because the volume of social web data is growing more rapidly than the volume of traditional web pages.”