More than 48 million internet users, or some 32 percent of online consumers, run anti-spyware programs that delete third-party tracking cookies, and nearly 38 million use aggressive anti-spyware that deletes nearly 75 percent of cookies, according to a recent report from JupiterResearch, writes InternetRetailer. Among Jupiter's suggestions: Technology vendors should lobby anti-spyware vendors to remove their third-party cookies from blacklists.

Companies that move to first-party cookies from third-party cookies experience a 10-15 percent increase in unique visitors, a 13-30 percent increase in repeat visitors and 10-30 percent more visitors attributable to specific marketing campaigns, according to Jupiter.

Recent Coverage: The Cookie Imbroglio

- Nielsen Accounts for Cookie Deletion in Visitor Count
- Tacoda CEO: Publishers Must Confront Intractable Cookie Problem
- eMarketer: Fear Not the Cookie Monster
- Jupiter: Wealthy, Web-Experienced Users Delete Cookies Most
- Making Cookies Digestible for Users
- WebTrends: Despite Net Ad Boom, Confidence in Web Metrics Shaky
- Burst Cookie Survey: Consumers 'Don't Understand, Say Maybe Useful, But Some Delete Anyhow
- Study: Quadruple the Number of Visitors Rejecting Third-Party Cookies
- Safecount Launched to Save Cookies, Back Safe Measurement
- Study: 27 Percent Weekly Clearing Cookies
- InsightExpress: Rumors of Cookie Demise Still Greatly Exaggerated
- Cookie Death Small Potatoes, More Product of Spyware Measures
- Atlas: Cookie Deletion Figures Exaggerated Wildly by Self-Reported Data
- Macromedia CTO: Yeah, Flash Makes for Good Cookie Replacements
- Cookie Death Causes Search for Successor
- Cookie Death Partly Due to 'Anti-Spyware' Tools
- Tacoda Tech Replaces Deleted Cookies
- Many Delete Cookies, Invalidate Ad Measurements
- House Removes Threat to Cookies in Spyware Bill