Why you need to backup your SHSH blobs? (iPad Jailbreak)

The Dev Team will soon be releasing an userland jailbreak without tethering called ‘Spirit‘. Userland jailbreaks shows current security holes in OS which even exists for non-jailbroken owners.  As such, Apple is likely to close them soon after they’re made public. One recent example of this is the SMS vulnerability exposed at Blackhat last summer.  Apple released new firmware to close that hole within a day. So before the jailbreak is released, and apple updates the firmware on their site, you will need to backup you SHSH Blobs. This will allow you to restore to an older software version, in case you need if you’ve accidentally update the firmware. Once apple fixes the hole, they will release a new version. Once the new version is released, and if in-case you need to restore your iPhone, it will only restore to the latest version provided by apple. There could be chances that latest version  may not have a jailbreak or cant be jailbroken permanently. However you can bypass this if you backup your SHSH Blobs. But if dont do it and once apple release new firmware you can no longer create the SHSH Blobs for the older firmware version, even if you didn’t upgrade.
If you want to use Spirit jailbreak stay away from iTunes latest update.