When it comes to professional networking online, nothing else comes close to LinkedIn. If you’re looking to find your next employer, your next star employee, your next CEO, CTO, or CFO, your next multi-million dollar investor, your next big client or your next co-founder, look no further than LinkedIn.

LinkedIn puts your whole professional career and your whole professional network on the web for all to see. It exposes you to the people you want to network. LinkedIn is a social network ripe with opportunities – But it’s not without its pitfalls.

One of the downsides of LinkedIn is how public it is. If you make a mistake on LinkedIn, it’s not just a matter of losing a follower or a fan – It’s a matter of losing a potential job opportunity. It’s a matter of not getting your company funded. Because LinkedIn is a network of your professional list, mistakes made on LinkedIn can really cost.

That’s why it pays to make sure you’re using LinkedIn right. Here are ten of the most common LinkedIn mistakes to avoid.

Mistake #1: Not Using a First Class Photo

Your photo shouldn’t just be good. It shouldn’t just be a great shot that someone took of you at a dinner party. It can’t even be just a good shot of you wearing a professional outfit.

The photo you use on LinkedIn should be taken by a professional photographer, in a professional context. There’s a lot that goes into taking the perfect professional photo that you just don’t see from an amateur photo, even a good one.

For starters, a professional will get the lighting just right. No part of your body will be dark and nowhere will look too light. They’ll use multiple light points to get it perfect.

They’ll instruct you on how to position your body. They might take several different shots to get the most credible looking photo. The shot itself will be taken with a high quality camera that retains good color and light data.

Finally, they’ll professionally color correct and touch up the photo until it really pops.

All of this you just don’t get with an amateur photo, even if it’s a good one. And it makes a difference. Browsers might not look at your photo and consciously think about whether it looks professional or not, but unconsciously people do make snap judgements. Having a great professional photo makes a difference.

Mistake #2: Half-Hearted Use of Groups

When people join LinkedIn, they’ll often take a peek in the groups section. They’ll also frequently join a handful of groups. But most of the time, after poking around a bit, people simply leave the groups section and never return.

That’s a pretty big mistake.

Groups are one of the most powerful features that LinkedIn has to offer. It’s not instantaneous – You’re not going to instantly get clients or jobs from groups. But in time, you can build incredibly powerful connections as well as build a lot of credibility in your personal brand.

Start by finding targeted, relevant groups for you. For example, if you’re in San Francisco and you’re looking for investors for your startup, join the “Bay Area Startup Network (BASN)” group. If you’re a lawyer looking for a job, join the “San Francisco Legal Network.” So on and so forth.

Get on the group and help other people. Answer questions. Demonstrate that you know what you’re talking about. Become an expert on that board. It could take as long as a couple months before people start coming to you with questions. The offers won’t be far behind.

Mistake #3: Selling and Marketing in Groups

Selling in groups has to be done in a subtle, relationship based manner. Any kind of overt selling is going to tarnish your reputation or get you removed from the group entirely.

Selling too directly in groups can take many forms. These include:

• Posting promotional threads.
• Linking to commercial events you’re hosting.
• Replying to other people’s threads with commercial messages.
• Sending private messages to group members with promotions.

All of these are mistakes. The best way to sell to a group is to build your reputation in the group. People will naturally come to you. It’s okay to subtly promote every once in a while, but never do anything that overtly looks like sales.

Mistake #4: Not Enough Recommendations

One of the most important things on your LinkedIn profile is your recommendations. People value reading recommendations because it’s a vote of confidence for you from someone else. If those other people are credible individuals, the vote of confidence would carry even more weight.

When someone lands on a LinkedIn profile and sees recommendation after recommendation, they immediately feel like you’re a trustworthy person. A lot of people will actually take the time to read over all your recommendations before deciding to contact you.

The flip side is also true. If someone lands on your LinkedIn profile and sees zero or only a handful of recommendations, their immediate reaction will be to distrust you. That’s just how the internet works: Because there are so many people vying for attention, everyone isn’t trusted until proven trustworthy.

If you want to make valuable contacts on LinkedIn and build your network, you need to have a large, robust base of recommendations. Reach out to all your co-workers, friends, clients and former employers and ask them to write a LinkedIn recommendation for you.

Mistake #5: Writing Over-Zealous Recommendations

This mistake is very easy to make. When people ask for recommendations, a lot of the time they’ll actually write the recommendation themselves and just ask the other person to post the recommendation. Unfortunately, these kinds of recommendations often lack juice.

More specifically, a lot of recommendations (especially the self-written ones) are full of excess praise but don’t touch on any specific points.

They might say that you were “great to work with,” “trustworthy” or a “fantastic person to have on your team.” All that is great, but a truly solid recommendation should go a step further.

It should give specifics. If you improved web traffic by 17% during your tenure, it should say so. If you were the go-to conflict resolution person for your company, it should say so. If you took the company from #5 in sales in the industry to #2, it should say so.

The more specific the better and the more results oriented the better. Praise is fantastic, but in order for the recommendation to hit home it has to be specific and grounded in the real world, not just in opinions.

Mistake #6: Not Proofreading Your Profile

If anyone sees any spelling or grammar mistakes anywhere on your profile, they’re going to be instantly turned off. LinkedIn is about putting your best foot forward professionally. In their minds, if you can’t even get your LinkedIn profile right, how can they trust you with their money, their work or their contacts?

Have a professional proofreader look over your LinkedIn profile. It’s extremely affordable, costing just a penny or two per word to have it reviewed. The whole thing would cost you less than $20. They’ll look for any spelling or grammar mistakes and fix anything that you might have missed.

Mistake #7: No Links or Bad Links

As versatile as a LinkedIn profile is, it still doesn’t give you everything you need to truly showcase everything you’re up to. To do that, you have to link to an outside website. Linking to an outside website allows you to actually demonstrate your skills, rather than just describe your past.

If you don’t have a link pointing to a professional website, you’re missing out on a big opportunity to sell yourself. You’re missing out on the opportunity to show your portfolio, to brag about past successes, to host client testimonials, etc.

An even worse mistake is having bad links from your LinkedIn profile. In other words, links that make you look worse rather than better. The most common and worst offender is linking to your personal Facebook profile that still has unprofessional photos from your past. If you’re going to link to Facebook, make sure it’s a Facebook account dedicated to professional networking.

Mistake #8: Having a Weak Summary

Your summary is generally the first thing people will read on your profile. It’s also often the only thing people will read on your profile. Your summary should hit hard and get people instantly hooked on the idea of contacting, hiring, buying from or investing in you.

Having a weak or mediocre summary is a big mistake. It does take quite a bit of time to craft a summary that really does the job. Every minute you spend on writing your summary is time well spent.

What goes into writing a great summary?

First, you should use up all 2,000 allotted words. The more you tell, the more you sell. Focus on your past achievements, especially concrete and measurable achievements. Share any stats on how you improved a company. Talk about specific problems that you helped resolve.

Put the highlights of your experience section in your summary. Of course, if they want your full background they’ll still scroll down, but you still want to be able to use the best of your past experiences in your summary.

Share anything that makes you unique or sets you apart from everyone else. Are there special skills you have that nobody else does? Have you done things nobody else has? Why should someone hire you rather than the other guy?

Wrap up your summary with your contact information.

Mistake #9: Not Using LinkedIn Answers

One of the best ways to leverage LinkedIn is to use it to build your reputation and establish yourself as an expert in a field. LinkedIn answer is a great way to do this – Yet so many LinkedIn users simply ignore this feature.

People come to LinkedIn answers to ask professional questions. People from all over the world post several thousand questions every single day. Answering these questions regularly can be a great way to network, build connections and build your reputation.

For example, let’s say your specialty is social media management. You can use LinkedIn answers to find people who’re struggling with social media. Look for their questions and answer them.

Do this every day. Some of the people whose questions you answer might hire you. You’ll also get a lot of attention from other people who see your question and liked your answer.

Mistake #10: Not Using a Custom URL

Using a custom URL on LinkedIn is free and makes you look a lot more professional. If you aren’t using a custom URL, it looks lazy and unprofessional.

How do you setup a custom URL?

Click your name in the upper right corner, then click “Settings.” Click “Edit Public Profile,” then “Customize Your Public Profile URL.”

These are ten of the most common LinkedIn mistakes that people make. Remember: Your LinkedIn profile is how everyone in your professional network will see you. In many ways, it’s much more important than Facebook or Twitter. Avoid these mistakes and take the time to make your LinkedIn profile really shine.