I get all sorts of spam in my Yahoo inbox every day. On gmail I get none.
Given the state of everything else, this is hardly surprising I guess…
This scenario can also result from having the hotmail and yahoo addresses for much longer, in the early days of the ‘net. When folks like us erratically threw out our email addresses to anyone who asked. I also use my yahoo and hotmail to sign up for random site access and newsletters that I don’t want hitting my everyday email account.