After graduating from the University of Michigan's business school in 2010, Kimberly Dillon landed a plum job as an associate brand manager at Clorox. But she was becoming restless and quit to work on her own startup as soon as her contract expired. For Ms. Dillon, the prospect of waiting three or four years for a promotion and the near certainty of having to spend a year doing a sales rotation with a retail partner like Walmart or Target (perhaps in Arkansas or Minnesota) were essentially deal-breakers. Plus , she had known from the outset of business school that her goal was to be at a startup.

"The tech world moves so quickly, and it was hard to be in a world of slow motion," said Ms. Dillon, who added that she turned down a job offer from Procter & Gamble after interning there in between business-school years. She's now VP-mobile marketing for a yet-to-be launched startup called Desti that 's aiming to improve travel planning on mobile devices. She he has a higher salary and said she has more people reporting to her than she did at Clorox. She also gets to own her company's marketing strategy.

"At tech companies, oftentimes you're building the brand yourself," said Ms. Dillon. "When I was at P&G and at Clorox, there would be eight agencies sitting at the table."

Ms. Dillon is not an anomaly. The marketing departments at P&G, PepsiCo and Kellogg traditionally have had their pick of A-list business school graduates. But lately the pool is shrinking as potential candidates migrate not just to startups but also tech companies and more entrepreneurial enterprises. The reasons are many, the potential to make more money faster and the lure of being able to shape your own destiny at a smaller company among them. But there's another explanation -- that as packaged-goods marketing relies more on analyzing big data, negotiating with procurement and obsessively proving return on investment, it may simply not be an exciting enough career path.

"The question I've been debating is whether CPG generally is viewed as as attractive as it was a generation ago," said PepsiCo's Global Chief Marketing Officer Salman Amin. "I think the jury's out on that ."

There's little doubt that the bar for talent is being raised as marketers become choosier in the pursuit of candidates with an analytical skill set. The demands of "big data" have had a big impact on recruiting, sometimes obliging CPGs to vet the field in a way that 's reminiscent of consulting firms such as McKinsey & Co. or Accenture. While it used to be that an MBA candidate interviewing to be an associate brand manager would be asked to assess the creative of an ad campaign, the line of questioning has grown much more quantitative in the last three to five years, according to Michael Malone, who heads the career center at Northwestern's Kellogg School of Management. Candidates are often given cases to work through; for example, they're asked what they would do if they were working on a brand due to launch in six months and learned that a competitor was launching a similar product. They might first be questioned on a macro level and then be given more details, such as the projected target for the product, to let them hone a numbers-driven plan.

But the very best analytical minds are apt to quaver at the thought of being pigeonholed at a traditional marketer with a narrow job description where they might be tasked with managing the discounts given to retailers, for example. According to Peter Fader, a professor at Wharton who teaches a popular class on predictive modeling, most of the best minds in customer analytics still go into consulting and investment banking, though he steers them toward companies like P&G. It's a given that CPGs can't offer as much money (associate brand managers typically earn a bit south of $100,000), but they also aren't giving students the range of exposure desired in jobs.

"The best and the brightest students are impatient and they want to wear those hats now and not wait five years to see what fits them best," he said. "They don't want to have four choppy little descriptions on their résumé." Mr. Fader said that the "wearing of many hats," as well as the granting of stock options, account for why more MBA's are headed to startups, and young digital companies like Gilt Groupe and Etsy with well-defined business plans and robust revenue streams that can no longer really be called startups are especially popular. The top recruiter at Wharton last year after Goldman Sachs and McKinsey was Amazon. He sees that as a step in the right direction, paving the way for more graduates to go to traditional marketers.

"Nobody goes into consulting or i-banking because they enjoy it," he said.

Pepsi's Mr. Amin wants to see business schools better prepare marketing students for a career at a CPG by teaching about the implications for competitive strategy of retailers promoting their own brands and about measuring the efficacy of media spending across channels. While he has a strong notion of what he wants, he said PepsiCo's share of the talent pool emerging from top business schools has effectively been halved over the last generation because more graduates are lured by the prospect of big money at banks and financial-services firms and, to a lesser extent, by startup culture. It puts the onus on CPGs to do a better job of marketing themselves, he said.

Or, as Mr. Fader put it, "If we can make the [marketer] job joyful, it can compensate to some extent."

At PepsiCo, that translates into emphasizing to recruits that they'll have an opportunity to work in emerging markets and in a collaborative environment.

This past year, the company hired 40 to 50 MBAs in the U.S., mostly as assistant brand managers and assistant marketing managers, and Mr. Amin noted that the recruiting process is only getting more rigorous in an interconnected world where a global perspective has become a key asset. Intellectual curiosity is more valuable, for example, since someone who's read up on the European debt crisis would be quicker to connect the dots and think about how commodity inflation might unfold and the implications for their brand's cost structure.

And while marketing has become more data- driven and brand management has become more quantitative, the need for individuals with the confidence not to get buried under the data has also grown. "There's almost too much data, and it can paralyze people," Mr. Amin said. "Another thing we look for is a level of maturity that may be higher than we [sought] previously."

Coca-Cola, which tends not to recruit its assistant brand managers straight out of business school, has also encountered a shrinking talent pool whereby digital-native executives need more persuading to come onboard at a multinational firm they may perceive as slow-moving, according to Kim Harley, human-resources director for global marketing. A lot of desirable talent is at startups as well as boutique agencies like Mother and Naked, places from which Coca-Cola has recruited. Part of the pitch is that they'll get to move around within the company, perhaps starting as a brand manager for Coke and being promoted in a couple of years to senior brand manager at Fanta, and then moved to China.

"They don't necessarily stay because they're loyal to the companies. They stay because the work is interesting or inspiring to them," said Ms. Harley, who noted that Coca-Cola North America has had only six associate-brand-manger positions open this year. "Fifteen or 20 years ago, it was much more about the stability and the loyalty and the vertical career ladder."

The problem of the smaller talent pool in which desirable candidates may be disinclined to work for a traditional marketer isn't just true for entry-level jobs. Demand for top digital talent is outstripping supply, according to Jon Suarez-Davis, Kellogg's senior director-global digital strategy, who said he's not only up against other marketers, but the Googles, Facebooks and Yahoos, not to mention a demand-side provider like Turn or a data player like BlueKai. Kellogg didn't have an in-house digital marketing team until 2009, and since then recruitment has largely hinged on hiring talent away from other CPGs and digital agencies. He said it's now a "buyer's market" for highly sought-after prospects who have leverage to set their terms.

"It's relatively easy to find someone with great marketing experience and it's relatively easy to find someone with great technology experience. But it's difficult to find someone who's got a great combination of both," said Mr. Suarez-Davis.

The phenomenon of MBA's gravitating to startups and entrepreneurship peaked during the dot-com bubble of the late "90s, according to Bill Sahlman, Harvard Business School's senior associate dean, who said that about 10% of Harvard's graduating class goes that route. However, there's some indication that this type of hiring may begin to accelerate.

Ben Horowitz, of the Silicon Valley venture-capital firm Andreessen Horowitz, recently argued in a blog post that startups should overcome their distaste for MBA's, a sentiment that 's prevailed in the tech community since the late "90s and early 2000s. (He cites a view once expressed by the founder of Mint, Aaron Patzer: "When valuing a startup, $500,000 for every engineer, and subtract $250,000 for every MBA.") But Mr. Horowitz said MBA course material has become more relevant to the startup world and "the world largely beat the arrogance, overconfidence and sense of entitlement out of the current crop of MBA's."

Startups have also probably attracted more interest in the past three years because finance jobs aren't as plentiful as they once were. (According to Kellogg's employment statistics, 7% of graduates in 2011 went into investment banking, brokerage and securities, compared with 12% in 2008.)

Even in the past few years there has been a shift in how many MBA's are interested in startup land. Brynne Zuccaro, who heads Foursquare's B-to-B marketing, recently checked her Duke alumni directory and couldn't find a single business-school classmate from the Class of 2005 at a startup. But her colleague Charles Birnbaum, a Wharton 2011 grad who leads mobile partnerships, said he has had coffee or calls with MBA's looking to pick his brain as many as five times a week.

"The feedback I give to people in recruiting offices is , "Do you want to work at a startup because you'll get more responsibility than you'd get at a P&G or a Coca-Cola? Because then you want to go somewhere small,'" he said. ""Or do you want to go somewhere with cutting-edge technology? [Because] not every startup has cutting-edge technology.'"

Oddly, even a failed startup can burnish an employee's résumé. "Typically we think of startups being very risky, since more than half of them are likely to fail," said Harvard's Mr. Sahlman. But unless a person has caused a failure or lied or cheated or stolen, in the world of entrepreneurship he's considered experienced, not damaged.