Blue Apron (APRN) will report its fourth-quarter earnings on Thursday, Jan. 31, and investors are expecting some positive results. The company announced it will reach profitability on an adjusted EBITDA basis in the first quarter, so the company should show some positive trends in that direction with its report.

But there's a lot to pay attention to beyond just the adjusted EBITDA number the company wants investors to focus on. Investors will want to read the earnings report and listen to the conference call to learn more about the following three things.

A box of vegetables and noodles from Blue Apron.

Image source: Blue Apron.

Improving average revenue per customer

If there's a single metric customers should be focused on right now, it's not EBITDA, it's revenue per customer. "The first indication of success in this is going to be that we would get to revenue growth before we get to customer growth," CEO Brad Dickerson told the audience at an investors conference last month.

Blue Apron's new strategic initiative is to focus on attracting high-value customers. It's focusing its marketing on the most effective channels and reducing the number of new customers. Blue Apron finally realizes its product isn't for everyone, but it could have a valuable niche audience.

If the strategy is effective, it will reduce its payback period -- the amount of time it takes the company to recoup its customer acquisition costs. Investors should look for commentary during the conference call.

So far the strategy isn't working very well, though. Average revenue per customer fell 4.9% in the third quarter. Meanwhile, management noted "the payback period for new customers has been extending, largely due to the acquisition cost per customer increasing" during the company's third-quarter earnings call.

Updates on strategic relationships

Blue Apron has made several strategic partnerships recently. It started with Costco in the first half of 2018, but the warehouse store chain stopped stocking its shelves with Blue Apron's meal kits last November. Dickerson said the company is targeting to resume its partnership with Costco this year, but there are no finite plans.

Meanwhile, Blue Apron developed delivery partnerships with Grubhub and Walmart's These partnerships are an important part of Blue Apron's on-demand strategy. Ultimately, Blue Apron wants to push customers who aren't the right fit for its subscription model to on-demand delivery options. Look for management commentary on uptake and potential expansion of its pilot programs with each partner.

Most recently, the meal-kit company partnered with WW to develop recipes for people following WW's Freestyle program. Management said it's seen "higher-than-expected demand to date." Look for further commentary during the earnings call.

Earlier this month, Blue Apron teased "a new offering specifically designed for online and brick-and-mortar retail." That sounds like it's developing new opportunities for partnerships, so pay attention to any new partner announcements during earnings.

Interest and depreciation

Management is focusing on adjusted EBITDA, but that doesn't mean interest, taxes, depreciation, and amortization aren't real expenses.

Depreciation and amortization increased 40% through the first nine months of 2018. That was largely due to the launch of Blue Apron's Linden, New Jersey, facility in mid-2017. Depreciation and amortization actually declined about 2.5% in the third quarter year over year.

Unlike other operational expenses, depreciation expense will be hard to cut since Blue Apron placed its new equipment in service prior to its shift in strategy to focus on its highest-value customers. That will be a burden as its revenue base continues to shrink.

Interest is another important factor to keep an eye on. The company decided to refinance its line of credit, extending its final maturity date a year and a half to February 2021. It paid down about one-third of its debt, but it's interest rate went up 2 percentage points as a result of extending its deadline. Interest expenses climbed in the third quarter, and it's something investors should keep a close eye on in the upcoming earnings report.

Investors sent the stock price skyrocketing when management said it expects to show profitability in 2019. That means there's little room for error in its reports. Pay close attention to see if the company is actually trending in the right direction.

Check out the latest Blue Apron Holdings earnings call transcript.