The wrong way to calculate ROI. Union Square Ventures's Fred Wilson says he often notices a lack of sophistication in the numbers he gets from entrepreneurs in calculating the potential return for an investor, not realizing that their projections assume a business will have an infinite life (when most don't). What entrepreneurs should be using, says Wilson, is the "cash flow method." Wilson outlines the steps and gives a sample Google Doc spreadsheet for you to play around with here. (Hat tip, Business Insider.

The start-up that can save your unborn child. The New York Times has the amazing story of Counsyl, the Silicon Valley start-up that says its test ($698 for a couple) can alert parents-to-be that they have the carrier genes for more than 100 rare genetic diseases.

Should you fire a co-founder? Venture Hacks has a nice guest post by Simeon Simeonov, a consultant to start-up companies, on when to part ways with a co-founder. "If you are behind the 8-ball and see your team as a key constraint, you should do something about it," he writes. "Don't wait for an investor or someone else to do it for you. The non-CEO co-founders can fire their CEO co-founder, too (or change their role and level of responsibility)." Of course, having to fire a co-founder means that you probably made a mistake when you hired your co-founder. Simeonov recommends trying to hire smart generalists and being honest with your self and your co-founders about what is in the best interest of the business.

11 tips for creating great content. Few people doubt that having fresh and interesting content about your business up on the Web is a great way to attract new customers and improve relationships with existing ones. However, running a business is time consuming enough, who has the spare time to post new blog posts or launch a new YouTube video? To that end, the American Express OPEN Forum has a list of 11 easy ways to create great content. Their main advice is for companies to think small. Rather than trying to post a blog entry the length of War and Peace, instead try writing a series of shorter blog posts that will be both easier to produce and more digestible for readers. Another great tip is to create content from things that your business is already doing. For example, the next time you or your team are giving a presentation at an industry event, why not film it and post it on YouTube?

Post iPad: a whole new category of smart phones. As risky moves go, entering the smart phone space right now ranks pretty high up there. But a start-up called QderoPateo is going a step further by making a phone for a market that doesn't exist yet (via GigaOM). The device is dedicated exclusively to augmented reality, a field that so far has garnered a lot of buzz but has shown few signs of rapid innovation. The company hopes to have a demo of the phone by spring and a launch in the fall. In the meantime, to get their foot in the door, the company is releasing an iPhone app called WorldLenns. So why isn't an AR iPhone app enough? Why build an entirely separate device? The new phone "uses triangulation between accelerometers, gyrometers, and GPS to calculate its user's location 10 times more accurately than GPS alone," according to the company."

Companies that have never had a layoff - do they exist? According to Fortune, they do. Even in a downturn, Fortune has found six of this year's best companies that claim to have never laid off an employee, or at least haven't had layoffs for more than 10 years. North Carolina-based business analytics software company SAS, family-owned supermarket chain Wegmans, and Mercedes-Benz USA top this year's list. Their secret to bucking the trend? Instituting hiring freezes, cross-training employees for different jobs, and accepting pay cuts at the executive level, respectively.

Who has more opportunities for advancement? A survey of almost 2,000 business professionals around the world conducted by the consulting firm Bain & Co. found a huge gap in perceptions among the sexes of whether men or women had an easier way to the top. Eighty-one percent of men thought opportunities to move into middle management didn't have anything to do with gender. Only 52 percent of women agreed. According to the Wall Street Journal, the study found similar perception gaps about whether promotions to the C-level were gender-neutral (66 percent of men, 30 percent of women). So who's right? In actuality, women leaders are harder to find in business. Research firm Catalyst Inc. found only 3 percent of Fortune 500 companies had women CEOs and 13.5 percent had female executives. The Journal offers a number of explanations: women aren't perceived as leaders by their colleagues (and sometimes themselves); women are assigned riskier roles (like cleaning up corporate messes); and men are better at developing career advocates. Orit Gadiesh, Bain's chairman, advises organizations that want to change those numbers to start quantifying what derails women. "You need to tailor it to the company--how many women you have, where they drop off, and what happens with promotions."

Next on Zuckerberg's list: Face-square? Business Insider is reporting that the goliath of social networking sites, Facebook, is toiling away on a feature that will allow its mobile users to "check-in" using GPS to broadcast their locations -- the key function of New York-based start-up, Foursquare. While Facebook has already "borrowed" a few components from other sites like Twitter (check out the recent "@" and "via" functions added to status updates), Foursquare is arguably still a fledgling network that might not be able to withstand a major player siphoning members from its userbase. Despite the looming competition, however, co-founder Dennis Crowley is putting on his brave face. "I think we're doing this better than anyone else and I think we'll continue to do so," he tells Insider. "We have so much stuff on the whiteboard that we haven't even touched yet."

How Pepsi got social media marketing right. Instead of spending money on Super Bowl television ads this year, PepsiCo is spending $20 million on social media marketing. According to Mashable, two of these campaigns--the DEWmocracy campaign and new Pepsi Refresh Project--are part of the company's larger plan to better engage customers with the brand through crowdsourcing. The DEWmocracy campaign will let consumers choose Mountain Dew's new flavor, and the Pepsi Refresh Project allows consumers to submit ideas for social good and vote for which projects should get a grant. "It's been great for us to have this really unique dialogue that we normally wouldn't have," says Brett O'Brien, Mountain Dew's marketing director. "It really has opened our eyes up." For a plethora of social media tips, check out's guide on how to use social media to build your business.

AT&T to shell out $2 billion for network improvements ... Mashable reports — and a collective cheer is heard across the nation. Whether the impetus was Verizon's string of commercials featuring that notoriously speckled map of AT&T's coverage, or the announcement that the company somehow wound up as the wireless data provider for the much-sought-after iPad, one thing's for sure: this is likely the best news all day for many an iPhone user.

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