that is fine if you have a tiny little site. If you are a big company, each micro site will use a piece of the larger set of files. if one use a,js b.js and c.js, when you concatenate you just lost 100% of cache if the user clicks a link to a side of the site that only uses b.js and c.js
likewise, try to load, un-concatenated, common libs from widely used free CDNs.
that is fine if you have a tiny little site. If you are a big company, each micro site will use a piece of the larger set of files. if one use a,js b.js and c.js, when you concatenate you just lost 100% of cache if the user clicks a link to a side of the site that only uses b.js and c.js
likewise, try to load, un-concatenated, common libs from widely used free CDNs.