That's great, until you hit the maximum number of invitations sent (3,000) and maximum connections (30,000).
So then what -- your LinkedIn profile is jammed with a bunch of people you're marginally related to for your professional network, which isn't going to be particularly useful to you.
This is an amazing hack but it will eventually get you a slap on the wrist from LinkedIn. When enough people complain about unwanted "invites," you will be given a warning about violating terms of service. Be careful about using this hack.