I've been a Hotmail user since 1997 (before MS bought it I believe). It's not my primary email, but I keep it active. When I heard about Outlook.com I went and set up a new account. (I didn't want to risk hosing my original account. There are a few horror stories out there.)
I found it generally has the same features as Hotmail (which MS has improved a lot over the last couple of years), but with a different look (Metro-ish). It has a couple of new things, but nothing I've found particularly useful to me. It was OK, but nothing special, that is, until I tried sending an email. That was when the train promptly left the tracks and in a big way.
First off it asked me to complete a captcha to prove that I wasn't a spambot. Okay, kind of irritating, but I played along. The captcha proved to be more than I could handle. I failed 3 times. I tried making sure I had the case correct, but some of the characters were so distorted it was impossible to tell. Frankly it was ridiculous.
Then I saw the little link that said something like "verify this account to avoid the captcha." Sweet! I thought. I'll do that and I'll be good to go! I clicked the link and it asked for my cell number. That was the only option. It wouldn't even use the alternate email address I had already provided. What!?! Seriously?!? I don't give my cell number to any website, much less one that is obviously going to mine my content for advertising.
Until they fix the captcha and requiring a cell number to verify an account, it's a non-starter for me. I'll stick with Hotmail. And if they eventually force it on me, I guess it will be the end of my Hotmail account. Their loss.

































