Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Chegg Inc. (NYSE:CHGG) were up 21% as of 12:28 p.m. EST Tuesday after the online learning platform company reported mixed fourth-quarter results, weaker-than-expected revenue guidance, and a content deal with Ingram Content Group.

So what: Quarterly revenue climbed 9% year over year to $84.4 million, helped by a 71% increase in digital revenue to $28.5 million, and hindered by a 7.6% decline in print revenue to $55.9 million. That translated to adjusted net income of $16.4 million, or $0.19 per diluted share. Meanwhile, adjusted earnings before interest, taxes, depreciation, and amortization came in at $18.8 million.   Analysts, on average, had expected adjusted earnings of $0.15 per share on slightly higher sales of $85.2 million.

For 2015, Chegg expects revenue in the range of $288 million to $312 million, including digital revenue of $133 million to $143 million. Full-year adjusted EBITDA should be in the range of negative $5 million to $5 million, and free cash flow should be in the range of $15 million to $25 million. Wall Street was modeling 2015 earnings of $0.15 per share on significantly higher sales of $353.1 million.

Chegg also announced a multiyear agreement with Ingram. Under the agreement starting May 1, 2015, Ingram will purchase the company's textbook inventory, which Chegg will continue to market under its brand. Consequently, Chegg will exit its warehouse operations by the end of this year.

Now what: Chegg CEO Dan Rosensweig said this is good news not only for students, who will get their books faster while still receiving the benefits of working with Chegg, but also for investors. "For our shareholders," Rosensweig stated in a press release, "this is very positive news as it means Chegg will no longer invest our capital in physical textbooks, while maintaining all the benefits and leverage our other businesses receive from textbooks."

Over the long term, this should also positively affect both gross margin and free cash flow, amplifying Chegg's ability to invest in its fast-growing, higher-margin digital services. In Chegg's earnings press release, the company noted it expects revenue by the end of 2016 will come fully from its digital business. All things considered, that's why I'm convinced Chegg investors have every right to celebrate today.