7 billion customers -- what's in it for you? That, plus the rest of the top-shared stories on LinkedIn this week

This week, we hit 7 billion people on planet earth. Or maybe 6.4 billion. Or 7.6 billion – the UN isn’t totally sure. Whatever the number, it’s huge and we’re growing fast — a rate “more bacterial than primate,” as the biologist Edward O Wilson wrote in The Future of Life.

The BBC, in the most-shared story of the week, built a tool for readers to chart where they fit in the flow of humanity. (Back when I was born, for instance, the planet had more of a small town vibe, with fewer than 4 billion people hanging around.) Business bloggers used the event to ask some questions about how their industries were going to suffer or profit from the mass expansion. As PharmExecBlog put it plainly: “What’s in it for pharma?”

Top 5 most-shared articles on LinkedIn (Oct. 28, 2011 – Nov. 4, 2011)

• The World at Seven Billion, 10/26 (BBC)
• People Who Use Macs At Work Are Richer And More Productive, 10/28 (Business Insider)
• Why Digital Talent Doesn’t Want To Work At Your Company,  10/27 (Fast Company)
• Inbound Marketing vs. Outbound Marketing, 10/30 (Mashable)
• Four Destructive Myths Most Companies Still Live By, 11/01 (HBR)

The PharmExec.com piece didn’t crack our top 5, but deserves a read. Many of the insights are relevant even outside the lab — and should get executives and entrepreneurs thinking about how to be ready for the next 7 billion.

The author, Bill Looney, explains why focusing on real solutions for the ever-growing “bottom billion” will help drive bottom-line growth. He points out that people aren’t just being born faster, they’re dying slower; concentrating on serving an aging population will be essential. And he shows how urbanization might drive new research. In pharma’s case, more people living in cities should allow drug makers to build efficient distribution pipelines, creating faster feedback between patients and researchers.

It wasn’t all just earth-altering news this week. Social-news junkies loved Mashable’s infographic showing the power and cost-effectiveness of two-way marketing — brands and consumer talking to each other — over one-way channels like banner ads. According to the research, compiled by social-media marketing firm Voltier Digital, 44% of direct mail is never opened and 84% of people skip TV ads.

And Energy Project CEO Tony Schwartz, who seems to appear on this list every time he pulls out his keyboard, spelled out the four myths businesses continue to believe in — and that are hurting their workers. No. 1 is multitasking, so quit checking Twitter and focus on this post!

Here are some of the top articles by industry sectors:

• The most-shared article by casino professionals was Forbes’ peek into the billionaires who are betting big on legalized online gaming in the U.S. There’s a Who's Who of Forbes 400 regulars: Vornado’s Steve Roth, Indiana Pacers owner Herbert Simon, Apollo’s Leon Black and Texas Pacific Group’s David Bonderman.

• Financial services pros shared Bloomberg’s surprising analysis showing bonds have been a better investment over the last 30 years than stocks. One researcher calls it, “the biggest investment theme that everyone has just gotten plain wrong.” The article also compiles some great data on related missed calls by market experts, including predictions of mass defaults by municipalities and rampant inflation.

• The top story in higher education was the unsurprising “Students Push Their Facebook Use Further Into Course Work,” from the Chronicle of Higher Education’s Wired Campus blog.

• Security professionals passed along CNNMoney’s follow-up to the RSA SecureID hacking incident from earlier this year. According to the article, 20% of the Fortune 100 were infiltrated, though it’s unclear just how far hackers got.

• In wireless, a TechCrunch story about Android fragmentation compiled by Michael DeGusta topped the charts.

• And, finally, folks in PR widely shared Ragan’s PR Daily list of the 53 signs you work in PR. Two takeaways: PR people barely sleep. And when they do sleep, they’re more likely to snuggle up with their phones than their significant others.

Have a great weekend! By the time Monday arrives, we'll be that much closer to 8 billion.