I have been wondering why social sites such as twitter and facebook use the concept of "More" results rather than paging, such as Next and Previous pages. Is this commonly used when paging through timelines? Or is there a performance reason?
Do you have any insight as to why one technique is implemented over another?
I think its usually a combination of:
As for performance there is a big difference between figuring out how many results meet a criteria and then slicing off a chunk for display vs just grabbing the next n records that meet the criteria. In one you have to consider every record in the target, in the "more" scenario you stop when you have enough records to display.