The only AdWords keywords that will perform well on search are ones that directly describe your product, e.g. "document syncing." To target a segment like legal professionals, use AdWords' Contextual Targeting Tool to build ad groups to target websites that your target market would visit, e.g. anything related to law.

The ratio of people seeking legal services to professionals providing those services is many-to-one. If it weren't so, lawyers would have to charge their annual income for a single consultation.

What this means for you is that the vast majority of legal-keyword searches will be moving the wrong direction -- from layperson toward lawyers.

If you spend your money on those keywords, you'll be wasting your advertising budget attracting the exact opposite of legal professionals.

If you'd like advice on which specific keywords phrases to target, you'll find yourself paying someone due to the time required to gather appropriate data. SEM agencies exist for this reason. You're also welcome to give me a call for recommendations or to outsource some of the keyword research. No day goes by when I don't research such questions, albeit from a different angle.

Adwords is not the best platform when you want to target an "audience" instead of search terms. I would suggest you to use Facebook - targeting lawyers - or may be display ads - targeting pages visited by lawyers - and call out your app details in the ad copy. This will make sure that the persons clicking on the ad are from your target audience and are interested in what you have to offer.

Paid search can only capture people who are looking for an app.... which is usually less than 3%. In general 3% of your target audience is looking to buy what you are selling.

A better use of adwords would be to use the display network, running banner advertisements that promote your app ONLY on sites that lawyers visit for industry news. In that case there are no keywords, its what sites does your audience visit regularly. I'd be happy to explain this more on the phone.

Keywords are the search terms that people might but into a search engine to find your website. The more likely someone is to use that keyword phase, the more important that keyword will be to getting your site popped up in the results - however, the more challenging it will be to do so because so many other people will be trying to do the same thing. However, there are also what are known as “long tail keywords,” which are longer phrases that someone might use to find what you offer, but fewer people would use them because they are so precise. For example, instead of “weight loss,” a long-tail keyword might be “weight loss supplements for diabetics.”
Here are few keywords you can use to target legal professionals:
1. lawyer
2. court
3. attorney
4. legal
5. litigation
6. solicitor
7. law
8. prosecutor
9. statutory
10. common law
11. barrister
12. counsel
13. sister in law
14. Harvard law school
15. law school
16. family law
17. lawsuit
18. civil law
19. free legal advice
20. law firm
21. law dictionary
22. international law
23. legal advice
24. law firms
25. case law

Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath