This week, the overall grades of three 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”).

This week, Reis, Inc. (REIS) falls to a D (“sell”), worse than last week’s grade of C (“hold”). Reis is engaged in the business of providing commercial real estate market information and analytical tools for its customers. In Portfolio Grader’s specific subcategories of Earnings Momentum and Earnings Surprise, REIS also gets F’s. For a full analysis of REIS stock, visit Portfolio Grader.

iPass (IPAS) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). 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 gets 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.

Slipping from a D to an F rating, Velti (VELT) takes a hit this week. Velti is a global provider of mobile marketing and advertising solutions. The stock gets F’s in Earnings Growth and Earnings Momentum. For a full analysis of VELT stock, visit Portfolio Grader.

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.