Investors looking for stocks in the Internet - Services sector might want to consider either Baidu Inc. (BIDU) or Shopify (SHOP). But which of these two stocks is more attractive to value investors? We'll need to take a closer look to find out.Everyone has their own methods for finding great value opportunities, but our model includes pairing an impressive grade in the Value category of our Style Scores system with a strong Zacks Rank. The proven Zacks Rank puts an emphasis on earnings estimates and estimate revisions, while our Style Scores work to identify stocks with specific traits.Baidu Inc. and Shopify are sporting Zacks Ranks of #2 (Buy) and #3 (Hold), respectively, right now. This means that BIDU's earnings estimate revision activity has been more impressive, so investors should feel comfortable with its improving analyst outlook. However, value investors will care about much more than just this.Value investors also try to analyze a wide range of traditional figures and metrics to help determine whether a company is undervalued at its current share price levels.The Value category of the Style Scores system identifies undervalued companies by looking at a number of key metrics. These include the long-favored P/E ratio, P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that help us determine a company's fair value.BIDU currently has a forward P/E ratio of 12.92, while SHOP has a forward P/E of 3,253.43. We also note that BIDU has a PEG ratio of 1.29. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. SHOP currently has a PEG ratio of 125.88.Another notable valuation metric for BIDU is its P/B ratio of 1.39. The P/B ratio is used to compare a stock's market value with its book value, which is defined as total assets minus total liabilities. For comparison, SHOP has a P/B of 16.13.These are just a few of the metrics contributing to BIDU's Value grade of A and SHOP's Value grade of F.BIDU is currently sporting an improving earnings outlook, which makes it stick out in our Zacks Rank model. And, based on the above valuation metrics, we feel that BIDU is likely the superior value option right now.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 Baidu, Inc. (BIDU): Free Stock Analysis Report Shopify Inc. (SHOP): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research