Agreed, manually sharing to multiple places is a waste of time. I honestly don’t think one should be sharing to multiple networks. Choose one based on the content of the share.

For me at least, I’m at the point where habit/instinct takes over, so I don’t need to spend too much time thinking at the time of actually posting.

My quasi-formula is quite quick working from top to bottom:

default Twitter – links or a statement less than 140 characters or when I want to mention someone specifically.
Facebook – more of a sentence or mini paragraph that won’t fit on twitter.
LinkedIn – business specific, or where I’m hoping to engage with a more business type audience.
g+ – haven’t figured out a specific target group here yet.

blog – slightly more structured thoughts and stories, you’ve got control of the user experience and how the see the post.

This post is a perfect example of how a blog post is better. The content and keywords now all remain on your domain, add value in terms of keywords and search indexing and also become a point of reference in the future should this topic come up in a discussion.

I guess one could consider sharing links on a blog as well and basically consolidate content onto the blog and then only share blog posts on other network, but I don’t think it’s as easy to engage with links as a post type on a blog and also the frequency of link shares wouldn’t really justify an individual post. Might be worth a post and a cover article, grouping links per category thus adding value to the links as well as sharing them.

This might end up taking a lot of effort though.

(sorry thinking out loud to myself there for a moment.)