We talked about that before we decided to do it, and it's a visual thing...
Which is easier to read and looks better / more professional?
Edited: Oops! LOL
Type them both out with the http one with the hyphen and one without ... The non-hyphenated version just doesn't look right when it's all lower case, in our opinion anyway.
I wouldn't usually go with hyphenated, but on this one it worked way better, in our opinion anyway. If the word started with an ascender, like ehow, we would have gone with non-hyphenated, but since we can't capitalize the first letter of the word in a domain name we decided host it on the hyphenated version.
We actually had it on the non-hyphenated version for about 24 hours and looked at it for a bit, then registered the hyphenated version to host it on.
ADDED: when you look at the non-hyphenated version it just doesn't read right, because your eye stops at the 3rd letter where the ascender is, and it seems like the 1st two letters should be a single sound, imo anyway.