Investors with an interest in Internet - Content stocks have likely encountered both Perion Network (PERI) and Shutterstock (SSTK). But which of these two stocks presents investors with the better value opportunity right now? Let's take a closer look.We have found that the best way to discover great value opportunities is to pair a strong Zacks Rank with a great grade in the Value category of our Style Scores system. The proven Zacks Rank emphasizes companies with positive estimate revision trends, and our Style Scores highlight stocks with specific traits.Perion Network has a Zacks Rank of #2 (Buy), while Shutterstock has a Zacks Rank of #3 (Hold) right now. Investors should feel comfortable knowing that PERI likely has seen a stronger improvement to its earnings outlook than SSTK has recently. However, value investors will care about much more than just this.Value investors are also interested in a number of tried-and-true valuation metrics that help show when a company is undervalued at its current share price levels.Our Value category highlights undervalued companies by looking at a variety of key metrics, including the popular P/E ratio, as well as the P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that have been used by value investors for years.PERI currently has a forward P/E ratio of 26.99, while SSTK has a forward P/E of 33.97. We also note that PERI has a PEG ratio of 2.57. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. SSTK currently has a PEG ratio of 2.61.Another notable valuation metric for PERI is its P/B ratio of 2.39. Investors use the P/B ratio to look at a stock's market value versus its book value, which is defined as total assets minus total liabilities. By comparison, SSTK has a P/B of 8.17.These metrics, and several others, help PERI earn a Value grade of B, while SSTK has been given a Value grade of C.PERI has seen stronger estimate revision activity and sports more attractive valuation metrics than SSTK, so it seems like value investors will conclude that PERI is the superior option right now. More Stock News: This Is Bigger than the iPhone! It could become the mother of all technological revolutions. Apple sold a mere 1 billion iPhones in 10 years but a new breakthrough is expected to generate more than 77 billion devices by 2025, creating a $1.3 trillion market. Zacks has just released a Special Report that spotlights this fast-emerging phenomenon and 4 tickers for taking advantage of it. If you don't buy now, you may kick yourself in 2022.Click here for the 4 trades >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Perion Network Ltd (PERI): Free Stock Analysis Report Shutterstock, Inc. (SSTK): Free Stock Analysis Report To read this article on Zacks.com click here.