This week, the overall grades of 10 internet and web service stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

Youku Tudou, Inc. Sponsored ADR Class A (YOKU) ratings are on the decline this week as the company earns an F (“strong sell”). Last week, it received a D (“sell”). Youku Tudou is an Internet television company. For more information, get Portfolio Grader’s complete analysis of YOKU stock.

Slipping from a D to an F rating, Marchex, Inc. Class B (MCHX) takes a hit this week. Marchex offers call-based advertising and related services, pay-per-click advertising and related services and proprietary traffic sources. The stock receives F’s in Earnings Growth, Earnings Momentum and Earnings Surprise. Equity and Cash Flow also get F’s. To get an in-depth look at MCHX, get Portfolio Grader’s complete analysis of MCHX stock.

This week, Unwired Planet, Inc. (UPIP) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Unwired Planet develops patents that allow mobile devices to connect to the Internet. The stock gets F’s in Earnings Revisions and Equity. For more information, get Portfolio Grader’s complete analysis of UPIP stock.

ChinaCache International Holdings Ltd. Sponsored ADR (CCIH) earns a D this week, moving down from last week’s grade of C. ChinaCache International provides a portfolio of services and solutions to businesses, government agencies and other enterprises to enhance the reliability and scalability of their online services and applications and improve end-user experience. To get an in-depth look at CCIH, get Portfolio Grader’s complete analysis of CCIH stock.

This week, E2open, Inc.’s (EOPN) rating worsens to an F from the company’s D rating a week ago. E2open develops and deploys enterprise software cloud solutions for businesses. The stock gets F’s in Equity and Cash Flow. For more information, get Portfolio Grader’s complete analysis of EOPN stock.

This week, iPass (IPAS) drops from a D to an F rating. iPass offers enterprise mobility services on a global basis by providing services that simply, smartly and openly facilitate network access from mobile devices while providing the enterprise with visibility and control over their mobile ecosystem. The stock receives F’s in Earnings Revisions, Equity, Cash Flow and Sales Growth. To get an in-depth look at IPAS, get Portfolio Grader’s complete analysis of IPAS stock.

This is a rough week for Velti (VELT). The company’s rating falls to F from the previous week’s D. Velti is a global provider of mobile marketing and advertising solutions. The stock gets F’s in Earnings Growth and Earnings Momentum. For more information, get Portfolio Grader’s complete analysis of VELT stock.

Travelzoo’s (TZOO) rating weakens this week, dropping to an F versus last week’s D. Travelzoo is an Internet media company that publishes travel and entertainment deals from travel and entertainment companies, and local businesses in North America, Europe, and the Asia Pacific. The stock gets F’s in Earnings Growth, Earnings Revisions and Sales Growth. To get an in-depth look at TZOO, get Portfolio Grader’s complete analysis of TZOO stock.

Homeaway, Inc. (AWAY) experiences a ratings drop this week, going from last week’s D to an F. HomeAway operates an online marketplace for the vacation rental industry worldwide, and offers homes, condominiums, villas, and cabins to the public on a nightly, weekly, or monthly basis. The stock gets F’s in Earnings Growth and Margin Growth. The stock has a trailing PE Ratio of 227.10. For more information, get Portfolio Grader’s complete analysis of AWAY stock.

CoStar Group, Inc. (CSGP) is having a tough week. The company’s rating falls from a C to a D. CoStar provides information and analytic services to the commercial real estate industry in the United States, the United Kingdom, and France. The stock also rates an F in Earnings Momentum. The trailing PE Ratio for the stock is 135.70. To get an in-depth look at CSGP, get Portfolio Grader’s complete analysis of CSGP stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.