“When a company debuts at $9 billion based on minimal revenues and no projected profit, is that a sign that their data is incredibly valuable, or that Wall Street has lost its mind?” asks Paul Noglows, managing director at Mesa. His question to a panel of social executives at “The New Marketing Math” event was likely on a lot of minds this week following professional social network LinkedIn’s IPO. Opening at $45, shares of LNKD shot up as high as $122.70 before closing at $94.25.

LinkedIn’s real value has been a topic of debate all week. The company’s enterprise value at the end of its first trading day was around $9 billion – 22.5 times its 2010 revenue, by some estimations. In comparison, Apple’s and Google’s ratios are 2.8x and 4.9x, respectively.

Some of the interest in LinkedIn stock is likely due to interest in social network stock in general. But the real value of LinkedIn, and all social networks, is in the massive amounts of data they’ve collected. LinkedIn’s future will depend on the network’s ability to filter out the signal from the noise, and quickly uncover meaningful insights from their growing database – both for individual users, companies, and researchers.

Expect LinkedIn and other developers to continue to release more ways to make the network’s data useful. Here are four interesting current uses of LinkedIn data.

Targeted marketing campaigns

LinkedIn’s ad platform allows advertisers to target users by factors including company name, LinkedIn group affiliation, and job title. LinkedIn’s professional nature makes it especially suited for targeting specific industries, companies, or roles – increasing ad relevance, potentially even outside of the network itself if partnerships with digital ad networks form.

Besides targeted campaigns, some companies are already using LinkedIn creatively to personalize marketing campaigns. Volkswagen, for example, ran a digital campaign in the Netherlands where users could compete against others in their LinkedIn network on factors like number of connections and recommendations. The simple campaign isn’t highly innovative – it can and has easily been done with other networks like Facebook – but it’s a first step toward more creative ways to personalize campaigns. This type of personalization will start to be really valuable when brands use these campaigns to spur longer conversations and relationships with prospects and customers.

Network visualization and clustering

LinkedIn Labs released InMaps early this year, providing a visual representation of users’ networks (pictured above). Using the map, clusters in a network become clear, and it’s simple to group connections based on a user’s relationship with them.

Imagine similar uses of LinkedIn data to identify clusters in other populations, like as an added layer of data in a company’s CRM tools. Marketers could use these clusters to identify highly connected influencers, or trends among customers – for example, finding a certain tablet computer to be popular among CMOs but less popular among IT users.

Aggregate trends

LinkedIn has a finger on the pulse of the employment world that networks like Facebook and Twitter lack. This puts the company uniquely in touch with employment trends like layoffs, turnover, and promotions, as well as trends segmented by region, industry, and role. For example, one LinkedIn study showed January, June, and July as the top months for US professionals to get promoted within their company. Another reveals “Peter” and “Deborah” as the most common names for CEOs.

Companies can use these trends to inform their marketing, among other things. For example, promotions in the IT industry are most common in April, July, and October. A B2B company targeting companies in this industry can use this information to time their messaging: “Four solutions that will make you your company’s hero – just in time for that promotion.”

Corporate intelligence

Similar trends can even be analyzed at the company-specific level. “I’ve been told that Goldman Sachs uses LinkedIn data to measure the stability of a company,” says Proclivity founder Sheldon Gilbert.  “If that helps them make better investments, then they have extracted quite a bit of value.”

Understanding your company’s (or a competitor’s) trends in hiring, turnover, and promotions can reveal a lot about the business – even more than just the company’s overall health. For example, if you notice a competitor seriously beefing up their product engineering department with professionals experienced in Facebook’s API, you could get an early indication of what they’re planning to develop for the social network.

Whether LinkedIn can maintain their high post-IPO value remains to be seen, but don’t assume it’s all hype. As rumors of public offerings from other social networks and tools swirl, the richness of their data – and their ability to glean useful, meaningful insights from it, fast – will determine their true value.