Yelp's (NYSE:YELP) third-quarter earnings report provided investors some relief from an otherwise horrific year. Shares of Yelp surged following the release of its third-quarter earnings report, as the local-reviews giant enjoyed strong revenue growth. During the company's subsequent earnings conference call, CEO Jeremy Stoppelman and CFO Rob Krolik provided some insight into the trends affecting Yelp's business. Below are five of the most important quotes from that earnings call.

Yelp's business model remains sound
Year to date, shares of Yelp have fallen nearly 60%. Disappointing growth in prior quarters has weighed on shareholders, and may have called into question Yelp's fundamental business model. During the call, Stoppelman defended the company's core advertising model, pointing to a study that lent credence to the power of Yelp's platform.

According to an August 2015 Nielsen survey we commissioned, Yelp advertisers reported more than $3.00 return for every $1.00 invested in Yelp ads. We drive valuable traffic to business because consumers on Yelp have high purchase intent.

The acquisition of Eat24 is going well
In February, Yelp acquired Eat24, a food-delivery business. Users can now order a meal directly through Yelp's website, and have it delivered to their homes or businesses. During the call, Stoppelman highlighted how the acquisition of Eat24 was benefiting Yelp's broader business, and how it was performing as a unit.

Now you can order food or make reservations directly from search results... this change drove a 10% lift in the number of platform transactions in the month after rollout. Since our acquisition of Eat24 we've also continued to optimize that experience. Eat24's revenue grew 73% in the third quarter and we have been pleased with its performance.

Yelp's costs rose during the quarter
Yelp's revenue growth was strong in the third quarter, but the company lost slightly more than analysts had anticipated. That seems to have been driven by increased costs -- particularly in the form of sales and marketing expenses. Krolik acknowledged the growth in sales and marketing costs during the call, and provided an explanation.

Total sales and marketing expense was approximately 58% of revenue in the third quarter, compared to approximately 53% in the same period last year. The increase in sales and marketing expense was primarily driven by the increase in marketing with our national TV advertising campaign and higher-than-expected sales headcount growth.

On Yelp's traffic
Because Yelp hasn't been consistently profitable in its history as a publicly traded company, investors have focused primarily on its rate of revenue growth and engagement. Krolik broke out Yelp's traffic growth during the call. While visits to Yelp's desktop website have actually declined, it continues to gain mobile users through its app. 

Unique devices accessing our apps grew 39% year over year to 20 million on a monthly average basis, lapping a strong uptick in app usage in the third quarter of last year. Average monthly mobile unique visitors grew 22% year over year to approximately 89 million. Average monthly desktop unique visitors was down 2% year over year to approximately 79 million.

Committed to $1 billion
If Yelp's full-year guidance proves accurate, the company will generate around $550 million this year. In the past, Yelp's management has provided long-term guidance in the form of a $1 billion annual revenue figure, a number it hopes to hit by 2017. During the call, Krolik reiterated management's commitment to that guidance, and offered some expectations on its long-term margin.

That $1 billion revenue [figure] is still achievable... we haven't specifically said what the margin is. I would imagine it's going to be quite a bit higher than 2015. And when we look at long term what our target margin is, we feel like it's going to be on an adjusted EBITDA basis 35% to 40%. And we feel pretty confident... we can see a lot of opportunity to increase our margin.

Sam Mattera has no position in any stocks mentioned. The Motley Fool recommends Yelp. 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.