Yes, I think it can be very useful and should complement existing criteria of scholarly reputation. Social media metrics/Altmetrics provide a broader range of impact than your "naked" publication list or CV.
ImpactStory has done a great job in promoting such a more diverse view of scholarly reputation and aggregating data from different sources. Here is a sample profile that shows how social media metrics can be combined with other - more classical - measures (such as number of citations on Scopus): https://impactstory.org/CarlBoettiger
Several publications on altmetrics also indicate that certain indicators from social media data are correlated with citations down the road.
Article Do Altmetrics Work? Twitter and Ten Other Social Web Services
Article Mendeley Readership Altmetrics for the Social Sciences and H...
Conference Paper Impact Factor 2.0: Applying Social Network Analysis to Scien...
I also think the answer is yes. I agree with Christoph, nowadays a tweet or a social mention can mean that you reach a bigger expert audience than a scholarly citation... Ways to measure your scholarly reputation need to evolve with time and new resources available.
Just today I saw this journal including "tweetations" among its metrics: http://www.jmir.org/article/tweets/2012
and I also checked this article:
Realising the Potential of Altmetrics within Institutions: http://www.ariadne.ac.uk/issue72/liu-adie
Yes it works. It is similar to other metrics study (Scientometrics,Informetrics and Webometrics), but not same.The Data collection, tabulation and analysis differs.In scientometrics, we use reliable Data set (Communicated data through documents and Online data bases viz. Web of science etc.) where as in "Social media metrics" very difficult to measure data and reliability is less.We should fallow Altmetrics and measure it. Now a days crowed computing also coming up.We can measure this also.
I do not know what exactly means for social media metrics "to count".
And just because we can count it, it does not mean that it should count as reputation.
Scholarly reputation counts when it comes from other scholars. It should not be adding to my scholarly reputation, for example, if I write popular blogs about football or celebrity gossip, even though I may have many followers who retweet me often.
At this point it is not easy to distinguish where reputation comes from. Offering myself as an example, I am relatively popular with journalists who, at the time of elections want to hear my opinion about fake accounts, privacy etc. But this does not make me a more reputable researcher.
I would contend that at this stage it depends on the discipline. Hard sciences and medicine are using altmetrics more than the social sciences. It can't hurt to track the number of times your work is mentioned but some research areas lend themselves more to popular notice than others. Just because you have a provocative title doesn't mean your research is worthwhile. I can't remember the exact situation but last year a top article in Figshare had a title that made it seem like the article had something to do with sex, consequently it got a lot of hits. I guess even those reading research sometimes act like they're still in the 3rd grade!
It is my hope that altmetrics will become more standardized with the work NISO is doing (http://www.niso.org/topics/tl/altmetrics_initiative/) so they will become more meaningful within the next few years.
The fact that some journals are now measuring altimetrics surely means that the landscape is evolving with respect to what needs to be measured in order to determine what impact ones research is having. However it may be a little too early for these kind of metrics to count towards ones scholarly reputation as there is still not enough known about what the numbers truly reflect. This may not be the case in another 2-3 years.
There is visibility which could help reputation but it may not help if those who judge you for tenure or promotion distrust social media or do not use it. Most researchers interviewed by us did not equate social media visibility with a recognition of the quality of the work, However with an increasing emphasis on impact among funders and within institutions, visibility may lead to impact and be recognised.
As Panagiotis mentions, as a researcher you really want the source of your reputation to be the 'scientific community' of your field. Now the question is: is scientific community present in social media metrics or it is left out, or maybe as Sue argues it is in some filed and not in some others.
There are other questions about altmetrics, one is related age, Do young researchers benefit more from these metrics than established scholars?
Certainly, Paul Erdos cannot benefit from altmetrics ;)
It is shown that works in Open Access venues produce more citations than works behind publisher pay-walls. In this era of easy access to information, if your work is not found easily, it may be ignored and not cited.
Younger scholars are more likely to be active in social media and online technologies, promoting their work, and placing their work online, accessible to others. Older scholars may rely on old ways of promoting their work which is rather slow in today's online world.
In that respect, younger scholars are more likely to benefit from altmetrics.
It depends what the institution you work for cares about. If their goal is to get their name and yours out among the public then sure, there is a value. However we should not assume that just because something we produce is popular among the public that it is good scholarship or useful academic work.
Any metric is important. The larger is the set of available metrics the greater is the set of scenarios that can be supported via the available metrics.
However, this does not implies that all the metrics are equally useful for "building academic reputation". Actually, what is the exact meaning of "academic reputation" and how to measure it is an open question that has to be agreed by the community in the large (including the academic but also the public).
For me metrics resulting from social tools capture the fact that the subject of the social post is having an impact, is worth to be spread by many.
One thing one should consider is how easily manipulatable these other metrics are. Can groups of people, or bots, could inflate artificially the altmetrics? If so, it should give us pause about their use.
I am optimistic that Jamali will get an answer from all the scholarly comments here in this forum. May I refer you to the view of Andrea Moncada who wrote on altmetrics on http://onthinktanks.org/2013/01/16/almetrics-the-pros-and-the-cons/. Away from that, scholar's presence/contribution to knowledge on social media has a lot of positive influence for himself and his institution. Such presence can also increase the webmetric ranking of an institution. However, except if such measurement is to be done without notice, it could be influenced easily and/or manipulated. I therefore suggest its use for measuring scholarly reputation because of its advantage for institutions alongside other parameters.
I believe that enlarging the base of value-added readership is one of our duties. Social media is a mean which we can use however ethically and conserving our integrity in the uploaded material.