Both Facebook Like and the Google +1 buttons recognize the two versions of the site as one and count both in their totals. How can I do that for twitter? Their are counts for both root domain and the www subdomain that are seperate when ideally they should count as the same thing since they are on the same site with both canonical urls defined and a redirect from the root domain to the www subdomain.
you can tweak your .htaccess (if you use apache webserver) to redirect www.domain.tld to only domain.tld and vice versa. more info and samples here: http://stackoverflow.com/questions/234723/generic-htaccess-redirect-www-to-non-www