The ratings of three internet and web service stocks are down this week, 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 more information, get Portfolio Grader’s complete analysis of REIS stock.

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. For a full analysis of IPAS stock, visit Portfolio Grader.

This week, Velti’s (VELT) rating worsens to an F from the company’s D rating a week ago. Velti is a global provider of mobile marketing and advertising solutions. The stock gets F’s in Earnings Growth and Earnings Momentum. To get an in-depth look at VELT, get Portfolio Grader’s complete analysis of VELT 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.