Steps for Buying Bicycle or Other Stuff

A newbie asked for advice to buying a roadbike & Steven Lim who got a dayjob dealing with safe cycling offered good advice:
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1. Identify purpose of riding, for fitness, for race, for triathlon, for touring..etc.
2. Set budget with a buffer of not more than $500 difference & stick to it.
3. Do research on various frame materials, carbon, Alu, Steel..etc, know their characteristics, pros & cons..etc.
4. Know your frame size, can get it from website of various brands or get it with a professional bike fit.
5. Do research on various brands, their size, geometry, their strength & weakness, models etc. 
6. Do research on various bike shops here that carry the brands you want & their sales & after sales service. But this one sometimes need trial & error as one man's meat may be another's poison.

With these process & information gathered, it is easier for you to shop for a bike & easier for decision making.
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I went through more or less the same questions when buying my commuting road bike. Just first two steps alone can narrow down to a small list of possible candidates. However some people just goto bikeshop blindly & let the salesperson influence them which i consider unwise. I encounter the same situation upon stumbling on an acquaintance who is at a bikeshop to buy a bike but don't know which kind of riding she is doing the most.

Is astonishing that some people intent to buy an item without knowing the primary purpose of using the item for.