What happened Shares of fitness company Nautilus, Inc. (NYSE: NLS) plunged as much as 23.9% on Tuesday after it reported third-quarter earnings. Profits beat estimates, but management lowered full-year guidance, and that's why shares are dropping. At 10:55 a.m. EDT shares were still down 19.5% on the day. So what Third-quarter revenue was up 9% versus a year ago to $88.1 million as retail sales jumped 15.8% to $53.5 million. Operating income was up 62.8% to $13.4 million and income from continuing operations was $8.3 million, or $0.27 per share. That easily surpassed the $0.23 in earnings that analysts expected. But that's the end of the good news. Image source: Getty Images. Management said the holiday season may not be as strong as previously anticipated and lowered revenue guidance to $405 million-$410 million, or about flat versus a year ago. Operating income is expected to fall 13% to 18% to $44 million-$46 million. Both revenue and operating income were expected to rise 5% to 7% in 2017 as recently as one quarter ago. Now what The new Bowflex HVT product isn't living up to expectations, which is a drag on results with declining TreadClimber sales. And until management figures out how to market the product directly to customers, its likely sales will lag expectations. Given the uncertainty around growth and the adoption of Bowflex HVT, I don't think this is a discount worth jumping on today, especially if increased marketing spending is going to crush margins for the foreseeable future. 10 stocks we like better than NautilusWhen 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 tripled the market.* David and Tom just revealed what they believe are the 10 best stocks for investors to buy right now... and Nautilus wasn't one of them! That's right -- they think these 10 stocks are even better buys. Click here to learn about these picks! *Stock Advisor returns as of October 9, 2017Travis Hoium has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.