These services go a step further than the free services by enabling you to perform sophisticated analysis on online activity. They're useful for market research, opinion tracking and product development. They can also cost tens of thousands of dollars a year.

Blogpulse - Intelliseek service that constantly sifts through Internet information looking for trends.

Blogview - Biz360 and with Feedster partnered to deliver a dashboard that helps you analyze online activity, including blogs and wikis.

Orchestra - Service from Cymfony, Inc. that provides tools to measure brand awareness and perception based on online activity.

Buzzmetrics - Merged with Intelliseek. Provides very high-end analytics combined with custom reporting.

Public Image Monitoring Solution - Product of partnership between IBM, Nstein Technologies and Dow Jones' Factiva that analyzes search results for trends about your market.