Accounts often come with one or a limited number of ip's. I have one account with 6 ip's and one that probably only has one... the WH4L one. What's the vital point of having them these days? 

Rob

Some services require a separate ip address while others just recommend a separate one.

SSL needs a separate ip, so for any service using SSL, you would need a separate ip. There are scenarios where you can use a shared certificate with multiple sub domains on one ip.

If you are reselling accounts, you would give the buyer their own ip if they are using SSL, or so they have some flexibility in their setup.

Sometimes it is just security related issue where you don't want to use host headers, like for web based sql administration or phpmyadmin, where you would want a specific ip and port for the connection.

There isnt much need for separate ip's these days. You can even run a dedicated server full of services (mail, sql, dns, websites, etc) off of 2 to 5 ip's depending on your needs.

I have read that if a domain has it's own IP, it will improve its Google ranking compared to multiple domains on the same ip.

That's rumor and I have no proof of this, but if it is true, then you might dedicate an IP to a 'featured' domain to push it up.

Interesting zoulou, thanks a lot.

DV