8GB of RAM is insufficient if you intend to multitask

Unified memory

How long its been since you last restarted?

I have the 8gb MBA, although in my case it's simply down to cost. On the basis of future-proofing, I would not recommend 8gb to anyone, and find even with my relatively light-moderate workflow that my system is regularly utilising swap. While mine was only ever intended to be used as a secondary machine for when I'm not at home, I have since switched to using it as my main machine as I've had some hardware issues with my main build. Either way, go for the 16 at minimum.

The "Swap" file does not do the same job as physical RAM. The "Swap" file is mainly concerned with providing a "Snapshot" to hibernate in case the computer goes to a stop. Then, it can also store excess temporary memory from RAM, but these days these are rare cases

Your options are bascially accept it always uses swap, sell it on ebay or chuck it in the bin

Are you noticing any kind of performance hit? If not it doesn’t matter and forget about it!

Yeah, can't multitask a lot with only 8 GB. Keep your tabs to a minimum.

You only have 8GB of RAM, it's going to use SWAP. The OS alone uses up 6GB or so of RAM just to get to your desktop.

8GB is MORE THAN ENOUGH! :D