So the marketing folk who design billboards, television adverts, radio ads, magazine ads, leaflets etc at a cost of hundreds of thousands of pounds are all wrong - and they should just use plain text in one colour, nothing flashy, just simple text or audio - the simpler the better? is that what you're saying?
I understand if you're LOOKING for a service it may be different, but that's not marketing or sales, its just 'order taking'.
For example, there is a van parked a 100 yards from me who offers concrete stenciling. His van is a white Transit, with black signwriting. It is the most boring, uninspirational things I have ever seen. If it was showing an example of what they do (a pic of a nicely designed patio for example) or some sort of offers or something it would be so much more eye catching and attractive.
And before anyone pipes up, I've seen this van almost every day for the past few months, but never really thought about it today til I started reading this thread.