These days getting a phone interview screen can be difficult due to the number of job seekers applying for the same job, but once you’ve got your foot in the door with the face-to-face interview, it is critical to have significant knowledge about the company so you can make a good impression on the potential employer. A quick Internet or Google search about the company will no longer do, as that is what every other job seeker can do and will do as well. You should be completing deeper research and show the potential employer you spent more than 5 minutes researching the company. Not only do interviewers expect you to have knowledge of the company, they will likely ask you questions about the company to see if you have done your research. Don’t lose the job offer because you haven’t done your homework! 
The first step would be to review the company’s website and go beyond just reading the “About Us” page. Learn the type of products or services they sell, the type of clients they focus on, and read about their Executive Team (typically all of the information is listed on their websites). If there is a product, service or something you didn’t quite understand, you can ask for further clarification during your interview, and this helps showcase that you have researched the company.
In addition to the company website, Google the company name and see what results come up. Look in the News section to read about what the press is saying about them; check up industry links or magazines. A good piece of career advice would be to review the links all listed on the first page of your Internet search for the company. As you read more information about the company, you will start to remember it more and when you use this information during your interview it will appear more relaxed and not forced.
Beyond web searching, use the social media platforms, LinkedIn especially, to see if you are connected to any of the employees within the company or past employees. If you find connections, email or call them and see if you can get them to help you during your interview process. During the interview, and when it is appropriate, mention that you are connected to so and so and mention that you enjoyed hearing what they had to say about the company. Having a personal connection to the company sticks with the interviewer and they have a “real” person within the company who they can ask about you.
With all of the research that you conducted, you should have compiled a large amount of information. The point of the research is not to show how much you have learnt, and regurgitate the information to the interviewer, rather it is a time to tailoring your interview examples and highlighting items that you see in the company that are commonalities with you and areas where your expertise could be useful.
Really good article for a Job Seeker! It’s very important to know in detail about the company for which you are attending interview and might end up working for it in future.