1.    Increase your visibility.
By having connections, there is a better chance that people will view your profile first when searching to contact someone about business that pertains to your industry.
2.    Improve your connect-ability.
Make sure that you fill out a complete profile.  Include your past jobs, education, affiliations, and activities.  This should act as an executive biography.
3.    Enhance your Google Page Rank.
Because LinkedIn allows your profile for indexing from the search engines you can say specifically what you want people to know about you.
In order to do this, start up a public profile then use the full view option.  Make your public profile URL to be your own; don’t let it stay among a bunch of numbers.  This is a change you can make and will help improve your visibility.  When you make comments or are blogging include the link to your profile page, this will also help increase your visibility.
4.    Improve search engine results.
You can promote your website to the search engines along with any blog you may have.  The LinkedIn profile has a place for your company and website and this information is indexed through LinkedIn and visible to the search engines.
5.    Check references about a company.
LinkedIn has a tool where you can check on a company and see how long they have been around, what references they have, and what that company has to offer.
6.     Be in a relevant job search.
You can use an advanced search option of LinkedIn that will help you find people that do the same work as you.  For example if you’re a plumber you could search, pipes, toilet’s, facets, etc… and a list of people and where they work will show up in the results.
7.    Iron out your interview.
Use link in to cover up that awkward silence during a conversation.  Use similar interests or professional areas to make small talk.  Know all there is to know about your interview before you step up to the plate.
8.    Is the company healthy?
See how healthy a company really is.  View feedback from employees.  Gauge their responses and look at the company’s profile and how long they have been doing business.
9.    Is the industry healthy?
If you are going to invest a large amount of money into an online business, or business of any other sort, look into that industry on LinkedIn.  For example if you are going to get into the mortgage industry talk to other professionals and find out from them how hard it really is.  See and compare who made it and who didn’t.
10.    New startups.
You can use your network to track startups and see who’s adventuring into different realms of business and see if your services are right for them.