You have to take the bad with the good.Yes, you get a lot of crap from headhunters via LinkedIn. But you can also get a lot of worthwhile approaches as well. The number of headhunter calls I receive since joining LinkedIn is huge, and for me, it is the only reason to be on LinkedIn.If you want to reduce the number of irrelevant calls that you get, put enough information on your CV on LinkedIn to help a recruiter decide whether a role might be suitable. This has two benefits: first, it reduces the number of inappropriate approaches you are likely to receive; and second, it increases the likelihood you will receive a call for a role that is a good match for your skills.Who do you think is more likely to get an appropriately targetted call:Joe Bloggs, Senior Manager, KPMGorJane Bloggs, Senior Manager, KPMGQualified Accountant ACCA 1996 with 15 years plus large scale multi-discipline, blue-chip multi-national work experience, covering a range of roles from Reporting Manager, Expenditure Manager, Project Manager, Director of Shared Services.Project Manager for FSSC Financial Shared Service Centre, concentrating on Financial Transformation business critical projects which included business process re-engineering, outsourcing activities and tighter fiscal control - also assisted in new ERP implementations(example cut-and-pasted from random LinkedIn profile, but you get my drift).Candidate 1 might get approaches for everything from IT implementation to HR to change management to performance improvement to competitive chess.Candidate 2 is likely to get focussed calls around finance transformation and shared services.Who do you think will have less of their time wasted?