I use Yahoo Mail* primarily. Why? I can't really say, but I'm sure that at one point in time, I had a really good reason and that the reason is surely long gone. But hey, it's better than Hotmail.
Each time I go to sign in, I wonder Why is Yahoo Mail apparently used exclusively by residents of San Francisco's Mission District?**
"What, this? Oh, it's just my ironic baby. Whatev. It works better on my husband." *Serious props seriously to Yahoo Mail for having used the sample address "free2rhyme@" since before this silly campaign.
**I have never been to San Francisco's Mission District. Or San Francisco, for that matter.

