Target your internet adds and pages for people with an IQ of 90 was the advise I recieved from a Harvard graduate who graduated at the top of his class. He taught me a few tricks in marketing and sales promotions years ago.
This is one of his basic ideas in marketing nursery stock. Its sort of like making presentations simple and for the stupid. No one will forget the message. For the many internet users who only spend 10 sec per site when they are surfing it is all important.
When I give directions on how to plant a tree I sometimes say things such as, " Plant with the green side up and brown side down".
This is short, simple, and easy to remember. If you give long, detailed directions you will lose up to 50% of your customers. A short and simple reply will be remembered, even if it is just, "Plant in groups of three, fall is for planting".