Huh? Why I what? Let's take it one step at a time:
GMAIL - a big (huge?) opportunity missed by Google
For almost a decade, there was one de-facto leader in the free webmail industry: Hotmail. Yeah, yeah, I know, there were others, most importantly Yahoo! Mail, but still - Hotmail was the first and until GMail came around (2004) I think it's fair to say Hotmail was the most prominent player. A monopoly? - certainly not.
At Google, some clever people understood that the free webmail industry is lacking some important features, and they took the challenge: GMail offered an inconceivably large mailbox (they started with 1GB, now it's almost 3GB), backed with Google search facilities, slick simple web interface, POP3 access, etc. They did one big mistake - left it in Beta phase for 3 years, based on invitation-only registration (at the beginning each user had very limited invitations available). I remember that when it started, people were searching with every lost friend whether he may have an invitation left in order to register. And it remained this way for long - much too long.
Why? Maybe it's because it was developed as part of Google's 20% time each employee can use to develop whatever she likes - and it took too long for management to give it proper priority? Maybe because they were afraid of getting out of disk-space if too many users would register? Bandwidth? Spam fear? Bugs that needed to be resolved?
Whatever the reason may have been, it's in the past and they missed the opportunity to become THE email world-leader, almost as they are the leader in web search. Because now, everyone (except ISP's, see below) offers large mailboxes with Ajax interfaces, and it really doesn't matter whether you get 1,2 or 5GB - most people never use more than 100MB, and by the time they will need more, storage cost will drop enough for it to be unworthy noting.
A last thing about GMail. Actually, it's about Google Accounts - there is a small security flaw... I recently created an account for a family member. She wanted the password to be some date. I know, it's bad security practice, but bear with me for a second, ok? Now, let's say the date required was 31 January 1999. When I typed as password "31011999", the passwords strength indicator says it's "Good". When, however, I typed as password "01311999" (i.e. MMDDYYYY instead of DDMMYYYY), the indicator says it's "Strong". Do I need to say more?
ISP's - why are they so stupid?
I don't know how it goes in other countries, but here in Israel, the default mailboxes you get from your ISP is extremely small (around 5MB). The result is that people don't use their ISP's mailbox for any important purpose, and prefer using their free webmail, such as GMail, which can also be accessed through POP3. There is even a movie that shows how to do the configuration, if you're not a techie.
Why do I think they are stupid? Let's look at the mobile phone analogy. In Israel there are several cellular companies, each with its own prefix. If I want to change my mobile provider, I know it will incur changing my phone number - so I will do it only if it's really really really worth it. I don't have to tell you the headache and costs incurred: service providers, clients, business cards, invoices, friends, etc. - all must be updated with the new number. Even the Israeli minister of communication understands the problem, and is actively trying to force the various phone companies to support changing provider without changing the number - until now without success.
With mail addresses it's similar - people hate changing mail addresses. Granted - it's much easier to change your email address than to change your phone number, and cheaper (keeping a forwarding account will cost you less than 1$/month), but still, after a couple of times you get sick of it and will try to avoid it as much as possible. Also, it is much more complicated, if not impossible, to force an ISP to support emails that belong to another provider. So basically, ISP's could bond their customers by giving them excellent email services (large mailbox, fast access, search facility, web access, etc), but they just don't see it. I'd even go further - they should provide FREE emails to everyone, not only to customers. Why? Well if I were a potential customer of some ISP, and I would see that most emails around me belong to that ISP, I would assume it's a big company that gives good services - and would be more likely to be drawn by it.
Ah, one last stupidity - I recently had to create an account at Netvision for a friend of mine. They still limit the usernames to 8-characters (only alpha-numeric I think). Hmm, WAKE UP !!!!