Instead of embedding an entire font, you may want to embed only a subset of the font – i.e. the characters of the font that are actually used in the text. Subsetting a font allows you to keep a file as small as possible, which is recommended especially if you do not plan to add more text (and hence more font characters) to the file. Note that when you combine two or more PDF documents that have the same font subset, duplicate character information is not deleted from the merged sets. This will result in a considerably larger file.
However, if it is not important that readers see the file in its original fonts, do not embed fonts at all, and let Acrobat use substitute fonts when necessary. This will produce the smallest file possible. Naturally, reducing file size will improve the file transferability.