Jamba (NASDAQ:JMBA) will release its quarterly report next Monday, and the smoothie-selling specialist has continued to impress shareholders lately with a rising stock price. But more importantly, Jamba earnings appear poised to start moving higher more sharply, and that could spell further gains for patient investors.

Jamba might sound like a simple business, but the smoothie chain has some interesting moving parts within its operational structure. With a mix of company-owned and franchisee-run stores, Jamba has two different ways of making money from sales of its products. Let's take an early look at what's been happening with Jamba over the past quarter and what we're likely to see in its quarterly report.

Stats on Jamba

Analyst EPS Estimate

$0.37

Change From Year-Ago EPS

48%

Revenue Estimate

$70.17 million

Change From Year-Ago Revenue

6.2%

Earnings Beats in Past 4 Quarters

1

Source: Yahoo! Finance.

Can Jamba earnings finally soar?
Analysts have had mixed views on Jamba earnings in recent months, although you have to be careful looking back at past numbers. After accounting for the stock's 1-for-5 reverse split, analysts have slightly higher June-quarter estimates but slightly lower full-year 2013 estimates than they had a few months ago. The stock has nevertheless posted a 7% gain since late April, again after accounting for the reverse split.

Jamba started the quarter off with its late April earnings report for the first quarter, in which the company posted a 4% sales gain on comparable-store sales gains of 1.3%. Jamba's company-owned stores did better, with comps of 3.6% offsetting declines at franchise locations of 0.9%. That didn't stop the company from posting a loss, but the winter quarter is a tough time for smoothie sales, and Jamba historically does much better during the spring and summer months.

So far at least, Jamba has been able to fend off competition from Starbucks (NASDAQ:SBUX) and McDonald's (NYSE:MCD). Indeed, it seems as though having smoothies available from more sources has only awakened interest in the beverages, and that's driving traffic toward Jamba's stores as well.

More recently, Jamba actually took a page from Starbucks' playbook and established its My Fruitful Rewards program. With Starbucks and Panera Bread (NASDAQ:PNRA) both having benefited greatly from having similar loyalty programs, Jamba hopes that its version will drive repeat sales and encourage customers to choose its products over those of its rivals. In addition, Jamba can collect customer data that should help it market more effectively and evaluate new initiatives over time.

In the Jamba earnings report, watch to see how the company's breakdown between franchise and company-owned locations works out this time around. Franchises offer better margins while company-owned stores give Jamba more control, and the shifting tides should give clues about whether Jamba will find greater overall success from one model over the other.

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Fool contributor Dan Caplinger has no position in any stocks mentioned. You can follow him on Twitter @DanCaplinger. The Motley Fool recommends and owns shares of McDonald's, Panera Bread, and Starbucks. 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.