Discoverability and messaging. If you like hearing from a range of recruiters, putting a keyword-filter-friendly resume on LinkedIn is a good way to make that happen. The quality varies pretty widely, but at least some of them are worth talking to in my experience.

(Stack Overflow Careers is another good spot if you're interested, with in my experience a lower incoming message rate but a somewhat higher average lead quality, and none of the irritation that LinkedIn generally creates in its users.)