Radio-frequency identification solutions provider Impinj (NASDAQ: PI) reported its fourth-quarter results after the market closed on Feb. 20. The company returned to double-digit revenue growth after dealing with a rough year of channel inventory corrections, and it now expects its typical growth trends to resume. Impinj is still not profitable, and its outlook called for a sequential earnings decline. But the top line is now moving in the right direction. Impinj results: The raw numbers Metric Q4 2018 Q4 2017 Year-Over-Year Change Revenue $34.6 million $26.9 million 28.8% Net income ($6.0 million) ($9.3 million) N/A Non-GAAP earnings per share ($0.09) ($0.28) N/A Data source: Impinj. What happened with Impinj this quarter? Impinj recorded its second consecutive quarter of revenue growth after three quarters of double-digit declines. Those declines were caused by a channel inventory correction that has now been resolved. The company shipped its 30 billionth endpoint IC during the quarter. Revenue was above Impinj's guidance range of $31 million to $33 million. Gross margin was 47.1% on a GAAP basis, and 49% on a non-GAAP basis. Non-GAAP gross margin was down 1.5 percentage points year over year. Adjusted earnings before interest, taxes, depreciation, and amortization was a loss of $1.7 million, compared to a loss of $0.9 million in the third quarter. GAAP operating expenses were unchanged form the prior-year period, with an increase in general and administrative costs offset by a decrease in sales and marketing costs. Endpoint IC revenue grew by 25% year over year, and systems revenue grew by 37% year over year. Sixty-three percent of total revenue was from endpoint ICs, with the rest coming from systems. Baggage tracking is one application of Impinj's technology. Image source: Impinj. What management had to say COO and President Eric Brodersen commented on the seasonality of the business during the earnings call: In the fourth quarter, lower endpoint IC volumes are partially offset by stronger system sales. In the first quarter, annual endpoint IC pricing negotiations typically impact both revenue and gross margin, while system sales are seasonally lower. Also in the first quarter, expenses tend to increase over the prior quarter. Brodersen also confirmed that the inventory correction is behind the company: As of today, we believe the inventory correction is resolved as we've said previously. And we do expect this period and going forward a return to more typical endpoint IC volume unit growth and trends overall. So from a channel inventory position, we believe that's been completed and corrected. Looking forward Impinj provided the following guidance for the first quarter of 2019: Revenue between $30.0 million and $32.0 million, up 23.5% from the prior-year period at the midpoint. GAAP net loss per share between $0.44 and $0.49, and non-GAAP net loss per share between $0.22 and $0.29. Non-GAAP EPS was a loss of $0.38 in the prior-year period. Adjusted EBITDA loss between $4.4 million and $5.9 million. The first-quarter outlook features a much bigger loss than the fourth quarter, although that could be the result of seasonality and product mix. With the inventory correction in the rearview mirror, Impinj expects another quarter of double-digit revenue growth. 10 stocks we like better than ImpinjWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has quadrupled the market.* David and Tom just revealed what they believe are the 10 best stocks for investors to buy right now... and Impinj wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of January 31, 2019Timothy Green has no position in any of the stocks mentioned. The Motley Fool recommends Impinj. The Motley Fool has a disclosure policy.