When you hire a trademark attorney, most will conduct a comprehensive trademark searches and opinion letters
Most attorneys that you hire will perform a comprehensive search. A comprehensive trademark search is a search that is conducted by a company that has access to federal and state databases, secretary of state databases, domains, and social media. When a comprehensive search is conducted, you’ll receive a report with names and rankings of similarity. An attorney will analyze the results and determine the risk of the trademark. She or he will let you know the likelihood that your trademark will receive registration. That means you aren’t wasting time or money on a mark that’s already taken. Additionally, you’re not putting yourself at risk by being sued by a registered TM owner. When you hire a trademark attorney, you’ll receive a recommendation from an authority that you can trust. 
You’re hiring an attorney whose focus is on trademark law
I don’t remember where I saw this but, would you hire an orthopedic surgeon to do heart surgery? No. The concept is the same when hiring an attorney for your legal issues. Most TM attorneys exclusively practice trademark law and have the education and skills so that you can rely on them. Most people believe companies like Legal Zoom who charge much lower prices can handle their TM issues. However, they are not practicing attorneys. Don’t believe me? Here ya go. 
This is directly from their website. If you have a trademark that has complications, they are likely not going to be able to help you.
Applications that are filed by attorneys are 50% more likely to be successful than ones that aren’t filed by attorney
I love statistics and believe that they really put things into perspective. When you hire a trademark attorney, you’re increasing your likelihood of approval. Most people are risk averse and don’t want to take the chance of rejection. Not only that, you are wasting money if you try to do it yourself and receive a rejection. It’s best to do it right the first time, because if you don’t, you still have to hire someone to fix it. In most cases, it costs more to fix it than to do it right the first time around. Attorneys have strategies that they utilize so that your trademark has the best chance of approval. Unlike business consultants who state they can file your trademark for you (btw that’s illegal and your application could be void if caught), attorneys understand the law and have a good take on whether or not your mark will be successful. 
83% of applications received an initial rejection letter
Read that again. 83% OF APPLICATIONS ARE REJECTED INITIALLY. Many times these rejection letters are avoidable because they are preventable. Some reasons include: similar trademark (that’s why attorneys do comprehensive searches), descriptive (an attorney can usually tell right off the bat), or an incorrect specimen (an attorney will give you the guidelines or grab your specimen for you). If you have no idea how to respond to this rejection letter, then you’ll have to hire an attorney anyway. Once again, that’s more money that has to come out of your pocket anyway. Now that you have a better understanding of why you need to hire a trademark attorney, you can make a better decision on whether or not you’re ready to move forward with the process. If you’d like a better understanding of the trademark process, don’t forget to grab The Trademark Roadmap below.