After four quarters in a row of declining year-over-year revenue growth rates, investors are finally expecting Starbucks (SBUX 0.72%) to return to growth as vaccinations ramp up and people are spending more time outside of their homes. Can the coffee giant live up to investors' high expectations for the quarter? We'll find out after market close today when Starbucks reports its fiscal second-quarter results.

Ahead of the earnings release, here's an overview of several items worth checking on when the company's report is posted.

A woman using Starbucks' mobile loyalty program.

Image source: Starbucks.

Comparable-store sales

One metric Starbucks investors probably watch closer than any other is the company's comparable-store sales growth, or growth at stores open for 13 months or longer. 

In Starbucks' most recent quarter, global comparable-store sales declined 5% year over year, driven primarily by a 19% decrease in transactions at these stores compared to the year-ago period. Helping partially offset a sharp decrease in transactions at the company's coffee shops, however, was a 17% year-over-year increase in average ticket size. On a geographical basis, Starbucks continued to see weakness in its Americas segment, where comparable-store sales declined 6% year over year. China comparable-store sales, however, increased 5% year over year, reflecting the market's rapid recovery following the COVID-19 pandemic. In addition, China's momentum provides some hope for a full recovery in Starbucks' Americas segment.

Starbucks management guided for fiscal Q2 comparable-store sales growth of 5% to 10% in its U.S. market, highlighting management's confidence in its overall business once again returning to growth. Going up against weak comparisons in China, when the country went into lockdown amid a COVID-19 breakout, management guided for 100% growth in comparable-store sales in the important market.

For the full year, management expects comparable-store sales to increase 18% to 23% globally. 

Investors should look to see if Starbucks can meet or exceed its fiscal second-quarter guidance and reaffirm its full-year outlook.

Starbucks Rewards program

Investors will also want to check on Starbucks' highly successful digital rewards program. Called Starbucks Rewards, the program's 90-day active members in the U.S. were 21.8 million in the first quarter, up 15% year over year. This was notably an acceleration from 10% year-over-year growth in the prior quarter.

Starbucks' digital customer relationships were one of the key drivers of the company's recovery from the pandemic, management said in Starbucks' fiscal Q1 earnings release.

Can Starbucks' keep up its digital loyalty program momentum even as more people are visiting stores in person?

Starbucks is scheduled to report its fiscal second-quarter results after market close today.