The New York Times has an article – The Best Kind of Traffic for Web Sites (free registration required to view) – about the value of visitors to retail web sites. The following chart shows the difference in value depending on whether you click through from a search result, from a paid search ad (i.e. displayed alongside search results) or direct (entering the address of the site in the browser/clicking on a saved bookmark):
Visitors who clicked on paid ad links were more likely to buy and spent more on each order than visitors who click on ‘unpaid’ search results, although nothing compared to visitors who go direct. The chart makes a compelling argument for a) having a short web address (I’m quicker at typing amazon.co.uk than I am at locating it’s bookmark); and b) giving customers a reason to want to come back (I often check reviews at Amazon) and hence remember the address or bookmark it.
The statistics were supplied by Engine Ready, an Internet marketing company, who analyzed 18.7 million visits over two years to web sites run by 27 of its 500 clients. You could ask ‘why those 27?’ A broader data set would be more convincing.