Career advices are very important for the proper guidance and development of a person's career. These are used to make important decisions that have significant and long lasting impact on a person's career. Career advices can be generic or individualized.
The generic advices such as those available on the internet are not targeted to a particular individual but address general situations. These are good for things like building a resume or preparing for an interview and can provide information that can help in making decisions like which career path to choose, when to change a job etc.
Individual career advices on the other hand are provided by professionals and are tailored to a particular individual. These professionals are either paid for advising or are part of a college or some other organization.
Not every job or career line is suitable for every one. The career decisions that are appropriate for you will depend heavily on your own capabilities, interest and qualification as well your personal inclination and situation in life. If a professional is to give you advice that is suitable for your unique situation; he or she must first know who you are. As you are more than the some of facts mentioned in your resume or portfolio, a conversation is an important part of this knowing process.
Personalized career advice is appropriate when you are making some critical and long lasting career decisions; such as when you are choosing a career line or looking for a new job. The advantage of the personalized career advice over the generic advice is that it is tailored to your specific needs and situation.
In order to give proper career advice the adviser must be aware of the situation in the job market as well as your own preferences, capabilities and personality. Without this information the advices would be hardly better than the generic advice available. Personal discussion is a very important part of knowing the individual. This may reveal some new information about the candidate's inclination or personality as well as emphasize some that are already known.
Ideally the conversation should be face to face as this way the advisor can observe the candidates body language as well. But in its absence a conversation over phone can serve as a compromise.
The importance of conversation in career advice depends on the type of career advice as well. Some decisions are more affected by the personality of the subject than others. If the advice provided is in the nature of information or tips that can help a person reach some career decision then the conversation is not important. On the other hand if the advice is a specific decision such as choosing a particular job or career which would be highly effected by the personality of the person, as a job which is suitable for a person may not be equally suitable to someone with a different personality, the conversation with candidate must be a part of the advisers decision making process.
As a general thumb rule you should not put much reliance on a career advice which is given without conversation. You should still consider it but keep in mind that it may not be the best suited to your particular situation.