I don't think music videos are particularly important for Techno, as there are very very few music channels which would air them, so it wouldn't generate much publicity overall. I think sleeve art on vinyls is an important thing tho, as that can catch your eye when you walk into a record store. If the cover art can get your attention, and give a feeling of the tracks on the release, then it is a form of publicity itself and can generate interest. We've all picked up records by artists we didn't know just because the name or the sleeve design caught our attention, and I think this is something techno artists can use to their advantage.