Quick! What Are These Companies Selling?

Can YOU tell by looking at these two vans (photos above and left) what service(s) the business is selling?
Me neither.
Just one more illustration that — when it comes to conveying a marketing message — less is definitely more.
See also, “Too Much Information” — Realtor Version“; and “Perils of Real Estate Marketing.”
For the record, the correct answers are: 1) plumbing; and 2) something called “tube art.”
P.S.: Both companies are based in Phoenix, AZ, where I snapped these photos last week (note the “480” area code).