Many studies, in academia and industry, in computer science and sociology (this one too), examine creation of new ties in social networks, but very few examine tie breaks and persistence.
Mor Naaman on a paper written with two colleagues (PDF (archived copy)) about a little-researched field in SNS: the end of digital relationships.
We have shown that network structure alone can significantly help explain the breaking and persistence of ties in Twitter’s online social network. We connected these findings to sociological concepts that may be at the root of the tie break phenomenon, such as strength of ties and status.
This, too, is an important field of non-use research: investigating why connections (or “use”, in a wider sense) vanishes. Indeed a under-researched field by far.