in general, ad units most beneficial formed box (rectangle), that is the size 336×280,300×250, and 250×250. Don’t use format 468×60 because most of all internet user aware that it advertisement. if you like to turn on vertical advertisement, best use format 160×600. important to remember, don’t to turn on vertical advertisement in site with structure layout 2 columns. to layout 3 columns, put advertisement in column middle, between content principal with sidebar site navigation containing.
