Comparing absolute change in Alexa rank seems fundamentally broken to me. It weights massively to early companies.
Snipshot's rank rose by nearly 80,000 - that's undeniably good, but 37 of the companies on the list had a previous rank of less than 80,000...
I would suggest comparing the delta of the log of rank, this gives a more interesting (to me) metric...
For example this bumps Newsblur up from a "meh" 23 to 1! And AnyPerk from an exciting 6 down to a not so cool (unless you like catches) 22 (not picking on AnyPerk, it's just the most demoted of the original top 10)
Under this change of methodology the biggest winner is WorkFlowy from 61->24, biggest loser's are Circle (39-67); FundersClub (40-68); and Cloudant (44-72)