Are you connecting TO people on Linked or connecting WITH people on LinkedIn
? The answer to this question depends on how you're using it. The only thing most people do on LinkedIn is send invitations to connect or accept invitations from others. If this is the extent of what you're doing, you are way under utilizing a very valuable business marketing/branding tool. It's kind of like joining a gym and never walking in the gym door. It sounds good to say you are a gym member but you'll never improve your physical condition.
Using LinkedIn effectively meaning logging in every day to your LinkedIn account for 10 or 15 minutes and browsing your news feed (left hand side of the LinkedIn page) to see what's happening within your network of business connections. Think of it as keeping up with your "business family" so you know what's going on with them and likewise, they know what's new with you.
But that is not the most important part, but this is. Take time to support (like/comment) updates that your connections post, but don't over do it! Also be a good source of quality helpful information that you actively share with your network. (Too much is not better!) LinkedIn might be business focused but it is still social media so the rule of thumb is: 80% of your posts should be focused on information that helps others and 20% of your posts can be used for self/company promotion.
Your personal LinkedIn profile needs to be high quality too and represent you well. (YES, put a photo!). If you ever want to set up a free LinkedIn company page, you'll need a strong personal profile in order to have access to creating a company page.
Please, start connecting WITH people on Linked or you'll end up with nothing but a LinkedIn online address/phone book (and one that doesn't generate many calls).