What is the impact factor of my short communication paper? Recently I published a paper in as a short communication in a Springer Journal in Natural Science discipline (Impact Factor 3.56). It was a short paper within 2500 words and 3 figures although the figures can be split up to 8-10 independent figures to make it a full length research paper.
I shared this paper in the social media after it got published. A few of my contacts asked me why I published it as a short communication, rather than as a full research article. They also mentioned that short communications are in general not treated as peer reviewed articles even if it underwent a rigorous review process. They have now suggested making it a full paper with some additional results.
My questions are:

Does this publication really have no Impact factor as of the Journal?
Does people cite the results published in short communications?
Is it always possible to extend the short communicated articles to
full length? If possible, then can I copy all or some of the point-to-point texts
and results already published in the short communications? Will it be
considered as self plagiarism?
Impact factors are assigned to journals not papers. No paper has an impact factor. The impact factor of the journal you published in, and the format makes no difference to that (as long as it is a peer reviewed format).

In my field (molecular biology/genomics/bioinformatics) people absolutely cite short communications.

Once a paper is published, you cannot publish exactly the same work as a full length article. You might publish further analysis of the same data, or the same analysis on different data, or different work that comes to the same conclusions, but you cannot just expand this same work to a new paper. Your new paper must also acknowledge the existance of the previous, and therefore would probably not be seen as as novel as the first one.