backup - What is the clockworkmod blobs folder good for?

I recently upgraded my clockworkmod recovery image to version 6.x and noticed that there's now a new blobs folder in the /sdcard/clockworkmod/ directory:

/sdcard/clockworkmod # ls -l
drwxrwxrwx    3 root     root          4096 Aug 27 14:46 backup
drwxrwxrwx 2329 root     root        131072 Aug 27 14:49 blobs
/sdcard/clockworkmod # ls -l blobs/
drwxrwxrwx    2 root     root          4096 Aug 27 14:48 000
drwxrwxrwx    2 root     root          4096 Aug 27 14:48 001
[... 2322 folders omitted]
drwxrwxrwx    2 root     root          4096 Aug 27 14:48 ffc
drwxrwxrwx    2 root     root          4096 Aug 27 14:49 ffd

What are those blobs good for?

Answer

Starting with version 6, deduplication support has been built into clockworkmod recovery. The blobs directory folder contains a hashed directory structure that holds the deduplicated files across all backups.

See the developer's Google+ post for more, in short:

TL;DR:
ClockworkMod Recovery now deduplicates files between builds. This results in way smaller backups.
Don't delete /sdcard/clockworkmod/blobs