Coca-Cola is still able to pull off surprises, as the higher-than-expected first-quarter revenue and profits show.

Consumers proved willing to pay more for Coca-Cola (NYSE:KO) beverages in its latest quarter, which enabled the soda maker to record higher-than-expected sales and profits.

Coca-Cola offset the continuing decline in soda volumes in the U.S. with price increases, more profitable drinks, a sharper focus on marketing, and cost reductions. Diet Coke, though, remains in freefall, with global volume tumbling 6% in the quarter, offsetting gains it made by Coke Zero, Sprite, and Fanta, according to earnings results released on Wednesday.

The key to Coke's success was a 3% worldwide price increase, which included a 2% increase in North America despite flat overall volumes. With a seemingly improved picture for the economy and employment, Coca-Cola took the opportunity to get consumers to pay up a bit more for its drinks.

Net income on a generally accepted accounting principles basis fell to $1.56 billion, or $0.35 per share, in the first quarter, from $1.62 billion, or $0.36 per share, a year earlier. But once one-time items were accounted for, Coca-Cola recorded $0.48 per share in earnings, 14% better than what Wall Street expected and 9% better than the first quarter of 2014.

Soda still going flat
Last month, Beverage Digest said the U.S. carbonated soft-drink market continues its unrelenting contraction, with 2014's nearly 1% sales volume drop marking the 10th straight annual decline.

Sparkling beverages still represent the vast bulk of Coke's total sales volume, some 68% in 2014, so persistent weakness in the segment remains an area of concern even if the company can record volume, price, and market share increases in still beverages, which accounted for the remaining 32% of last year's volume.

Still beverages remain strong, but volumes are uneven. Juice and juice drinks, for example, saw volumes drop after price increases went through.

The company was able to do all that, as growth in ready-to-drink tea, value-added dairy, and packaged water helped push global still beverage volume 1% higher. Yet how much more growth the beverage giant can generate for the rest of the year remains to be seen.

The global economy could be teetering toward another crash as Greece careens toward financial collapse -- again. Meanwhile, Coke's new premium milk product, Fairlife, has a dubious chance of success. It might have created some buzz, not all of which was good, but asking consumers to pay significantly more for a drink they're already drinking less of is counterintuitive at best, and foolhardy in the main.

Big changes still needed
Still, CEO Muhtar Kent believes these are early indications that the strategies he has put in place will bear fruit, though 2015 remains what he called a "transition year." He asks investors to have patience and give these efforts time to succeed, even if there are hiccups, as macroeconomic conditions remain volatile.

One investor not willing to wait is Wintergreen Advisers, which last year mounted a mini-revolt against Coca-Cola's executive compensation policies and recently began agitating for the beverage giant to initiate "transformative strategies" such as what H.J. Heinz engineered when it went private last year and made a play for Kraft Foods (UNKNOWN:KRFT.DL) last month.

The global money manager thinks Coca-Cola has taken baby steps in making necessary changes but has barely scratched the surface on bold stratagems that could increase shareholder value.

No one's enjoying Diet Coke much these days, as volumes have plunged globally.

Losing its fizz?
While Coke's stock popped 2% higher at the market's open today following its pre-trading earnings announcement, shares have since eased back, perhaps in recognition of a number of roadblocks ahead.

In addition to the softness still present in North America, many of its other markets only benefited because of higher prices and gaining six additional sales days, as well as Easter's shift into the quarter. Price increases are fine when you can take them, and if sales grow commensurately afterward, they pad the bottom line.

But they also help mask problems that could be lurking below the surface that will become apparent if any further volume gains fail to materialize. For example, juice and juice-drink volumes took a hit when Coke raised prices to cover higher input costs; a similar effect could spread to other business lines.

Nonetheless, Coca-Cola's first-quarter effort should be commended, if for no other reason than Wall Street has set the bar of expectations fairly low. There is potential for a recovery, but it might yet require implementing some of those transformative strategies that activist investors are calling for before real change is recorded.

Coke's quarterly sales and profits were good, but don't pop the bubbly yet that they will do as well through the rest of the year.

Follow Rich Duprey's coverage of all the most important news and developments in the leading brand name products you use. He has no position in any stocks mentioned. The Motley Fool recommends Coca-Cola. The Motley Fool has the following options: long January 2016 $37 calls on Coca-Cola and short January 2016 $37 puts on Coca-Cola. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.