The Strategic Name Development Blog has an excellent post about the notion of pormanteau (a word that is formed by combining both sounds and meanings from two or more words), titled Company Naming: What’s in Your Portmanteau?:
It was Lewis Carroll who first used the word “portmanteau” to describe a word made up of other words – in this case, the words he had invented for the poem “Jabberwocky.” While some portmanteau words, like “guesstimate,” have an immediately obvious meaning, “brillig” and “slithy” are not so obvious.
There are two reasons portmanteaux make good company names. The first is that, as coined words, they are much easier to trademark than natural words. (But you still need to check the trademark database to make sure no one else invented the word before you did.)
The second reason for choosing a portmanteau name is the ability to evoke two or more concepts with one word: Verizon, for instance, is a combination of the Latin word veritas, meaning “truth,” and the English word “horizon.”
More resources on the subject: