Can marketing research make or break a marketing plan?

There are different type of marketing researchs for different stage of project. What important is to use the right technique for the right objective. For example, I would use maxdiff to check any small conversion would be noticable, kano to find the next big things. I'm not an expert on this, bit remember the saying if you only have hammer, everthing looks like a nail.

Charity, Very good points. I have seen too much market research paralyze a business from moving forward with a very good product, so I agree. There definitely has to be some semblance of balance between waiting for additional research and moving forward while you may still have first-mover advantages. However, moving forward without sufficient data to back up your plan is the quickest path to failure. Too many assumptions can lead to too many risks, which can torpedo a new product before it gets an opportunity to penetrate the market.

Both. Make the correct inference, however. Market research and data implied in 1995 that no one would ever use their credit card online. People thought Facebook was a fad or stupid in 2004 now they are on it all day. Not everyone knows what they want so factor in all the phychological and innovative underpinnings for your product when evaluating research.

I would not say make or break marketing plan. This would be like you are trying to prove your plan or marketing idea. Your marketing actions should be based on your research. Properly done research should show you where and to whom you should be marketing. Even maybe the tactics you should be deploying. Never use marketing research to try and prove your assumption or believe. This is lead you to bias research and flawed marketing. Research should come before you pen the majority of the plan.