There is a form of expression that is valid in English, which is to capitalize the first letter of every word, including the link words, on a newspaper article title for example. Translate the text in other languages, such as French, and this rule does not apply anymore.
Considering this, I keep seeing blogs and sales pages written in French who disregard French grammar by using the capitalization of every word's first letter in titles. Some message boards also convert people's text into this form on the titles of the different threads.
From a French perspective, reading such text makes me think that it was automatically translated from English with no human intervention in order to reach to a broader audience, thus lowering my perceived quality of the content or anything that is being sold by the use of such text.
Also, reading a capital letter at the beginning of every word in French makes me believe that the writer is strongly raising his voice at each word.
The question is : if it is often used in a selling context, this thing must work for a reason. Is there a kind of better impact by the use of capitals, so much that it is worth disregarding the current language's grammar rules?