It’s both a positive and a negative factor  for a candidate if he/she has been into different jobs throughout his/her  career till date. 
Frequent changes in job  profile and job-shuffling raises doubts in the interviewer’s mind regarding  your loyalty, longevity and consistency. An organization spends a considerable  amount of money on a new employee’s recruitment, hiring and training. Hence,  your loyalty and longevity is a matter of concern for the employer. 
On the other hand, it’s  also true that experience in and exposure to a number of industries is the need  and demand of today’s job market. Gone are the days when people used to spend  their entire life with one employer or in one industry. 
You need to give a  HUMBLE answer to this question. Construct your answer around the following  points:
1. Do mention about the ‘learning curve’ of each  job. Tell them that working and learning/growing shall take place  simultaneously. When once stop learning anything from a particular job, then,  it might be an indication for considering a job change.
2. Tell the true reason behind such  job-shuffling. This shall save you from mugging up your answer and lack of  justification. 
3. Highlight the positive attributes which you  like about the job-profile that you are seeking.
4. Don’t complain about how you dislike your  current job or your current boss. It gives a very negative impression about  you. 
Note: If the interview has been smooth in all other  aspects except for this particular question, then, you will surely make it  through the interview. Otherwise this question has potential enough to drag you  back. 

Now, it’s time for 'participation':
*Assume that you are sitting in the interview room now.
*You have been asked to ‘Why have you been into so many different jobs’. Go ahead; give it a try on how to answer the same. Post your own answers and get them reviewed .

Why have you been into so many different jobs?