LinkedIn, which calls itself the social network for professionals, is adding a service that provides members with pay information for a variety of jobs, including a breakdown by such factors as location, industry, education and experience. The new service comes two weeks after Glassdoor, a competing job site, introduced a feature that promises to help workers determine their “personal market value” by comparing their current job title, salary and related information with data from other workers and current hiring trends. Both services are free and promise to go beyond more generic salary tools — offered by job sites like Indeed, PayScale.com and Salary.com — by combining computer analysis with the most up-to-date information gleaned from workers, labor reports and other sources. LinkedIn recently began offering training suggestions for workers, based on their current jobs or career track, which tie into the online courses offered by its Lynda.com subsidiary. LinkedIn recently agreed to be acquired for $26 billion by Microsoft, which wants to augment its own commercial software — including email and calendars used by workers, as well as management and corporate sales programs used by employers — by incorporating LinkedIn’s extensive database of professionals and their resumes.