The intention is to avoid "hello"'s negative connotations of Hell, despite the fact that such connotations would not occur to most level-headed people and the two words aren't related anyway, and replace it with a supposedly more inspiring reference to Heaven. As Canales' website proclaims, "The 'O' is not enough to hide the most negative word (Hell) printed in every dictionary", while the "Universal greeting 'HeavenO' is a symbol of Peace, Friendship and Welcome."
In 1997, Canales successfully persuaded officials of Kleberg County, Texas, to officially adopt "HeavenO" as the county's preferred form of greeting. Subsequently the greeting has grown in popularity within Texas and beyond, being adopted by some businesses as the correct way to greet customers. However, Canales' right to promote the word as his own invention has been challenged by others who claimed to have used it previously.
According to Canales, his "HeavenO" campaigns have led to the decline of "hello", even where "HeavenO" is not adopted. For example, Wal-Mart no longer uses "hello" on name tags, and Yahoo has replaced it with "hi" as a greeting.
Of course there is no etymological link at all between the words "Hell" and "hello," the latter deriving from older forms such as "hallow" and "hullo". Ironically, this common greeting probably has its oldest origins in the Germanic word "hailæn" (or Old English "hælan"), which means to heal, to cure or to save, either in the physical or religious sense.
Linguistic arguments such as these are one source of criticism of the "HeavenO" trend, along with the fact it's more than a little bit silly. Other common objections among Texans include "What's wrong with, 'Howdy, y'all?'"
Essentially, "HeavenO" is no more meaningful than "hello".
 See also
- HeavenO - official website