It's important to include a small logo, that way if the graphic is not correctly attributed to you, it is still associated with you or your company.  Include a small non-obtrusive logo on the bottom of the graphic.  Professional photographers, infographs, etc. usually include a logo, and perhaps a link.  Just be sure that including it doesn't take away from the graphic.

It's good practice to include spacing but Google can make the distinction.  That being said, I would recommend just using spacing and no pipes if you don't have space for three characters it looks much better.