Verizon Communications (VZ 0.90%) will report earnings on Tuesday July 24 ahead of the opening bell. After beating expectations on both the top and bottom lines in the first quarter, management looks to extend its streak of earnings wins. The analysts' consensus currently calls for Verizon to report $1.14 in EPS on revenue of $31.74 billion.

However, Verizon investors will want to look beyond the top and bottom lines when the company reports its results. Here are three things investors should look for in the company's earnings release and additional commentary during management's conference call.

Verizon's unlimited logo in a warehouse.

Image source: Verizon.

Wireless service revenue

Smaller competitors like T-Mobile have historically put pressure on Verizon's wireless service revenue. First, T-Mobile separated service and equipment billing, and then it introduced unlimited plans.

At this point, Verizon has shifted most of its subscribers (81%) to unsubsidized equipment plans, alleviating pressure on service prices. Additionally, the second quarter was the first full quarter last year in which Verizon offered its new unlimited plans. The early adopters of unlimited plans were those that could save money from their metered plans, putting further pressure on service revenue.

CFO Matt Ellis reported during the company's first-quarter earnings call that Verizon saw a year-over-year increase in service revenue for the month of March. Complicating matters is an accounting change this year with the new tax code, so investors may see a drop in the reported financials. Look for supplementary information from management either in the report or on the earnings call regarding how service revenue compares on a like-for-like accounting basis.

Wireless EBITDA margin

Verizon saw a 270 basis point year-over-year expansion in its wireless EBITDA margin in the first quarter. Look for that growth to continue, especially as Verizon migrates more customers up to its unlimited plan from lower-priced metered plans.

Verizon isn't relying on bundling economics like other carriers, particularly AT&T (T 1.10%). AT&T is bundling its television packages and additional content with its unlimited wireless plans, and it's putting pressure on its EBITDA margins across all of its segments. The company's wireless EBITDA contracted 350 basis points on a like-for-like accounting basis in the first quarter.

Investors should look for Verizon to avoid a similar fate, since it's mostly relied on its strong brand and network to keep attracting customers. It recently introduced a higher-priced plan, which probably won't affect second-quarter results, but it's a good sign that customer additions have been strong. Pay attention to net additions and churn rate, as those will have an impact on service margins as well.

Oath

Oath is the combination of Verizon's acquired AOL and Yahoo! properties. Oath was a bit of a weakspot in the company's first-quarter results. While some decline in revenue from the seasonally strong fourth quarter was expected, Verizon saw a 13% sequential decline in revenue for the fourth quarter to $1.9 billion. Management said it expects Oath revenue to climb sequentially throughout the year, so investors should expect to see improvement on that line in the second quarter.

One big question mark surrounding Oath's results, though, is how go90 will impact the results. Verizon shut down the mobile video app less than three years after launching it and spending over $1 billion on content. Poor performance from go90 could have an impact on revenue growth for Oath.

On the other hand, if Verizon was unable to make go90 profitable, it's best that it ditches the dead weight and focuses on the Oath properties that are making money for the company. Investors should look for further commentary from management about Oath's efforts to integrate legacy AOL and Yahoo! properties and the impact of shuttering go90.

Investors interested in Verizon will want to pay close attention to its wireless business -- particularly service revenue and margin. Investors should also be looking for growth from Oath, which still has great potential to be a profit center. This article should give investors a starting point for how to look past the headline numbers and determine the health of the business when Verizon reports earnings next week.