First things first, what are addon domains
When you buy a hosting package you often have limited or even unlimitted addon domains, but what are they exactly ?
At hosting we call the main domain attached to the account the ‘Main Domain’ all other domains attached to the account (this could be other websites) are called addon domains; or sub-domains. There is also another term you may hear which is Parked domains but these are distinctively different from addon or subdomains as they never have their own content but forward to a existing content under one of your domains, subdomains or addon domains.
So what are Unlimited addon domains
Unlimited addon domains means that your host lets you add as many addon domains to your account as you wish, but there are a few things you have to know about this as these can limit your account severely and can also be a huge security risk with a very large impact to your account. The term Unlimited is however misleading in many cases as each domain will occupy some diskspace, IO and bandwidth these will still be the limiting factor.
 The good of Unlimited domains added to your account
– Cheap, you do not need to order a new hosting package for each domain you are going to host
– Easy, you can manage all these accounts from your cPanel
The bad of Unlimited addon domains added to your account
– Resources, each site will use resources, especially shared hosting providers will limit the resources per account; so basically all your domains ‘share’ the resources the hosting provider added to your hosting account.
– Security, all accounts run under the same account; even if the host has a solid security system in place which keeps all users correctly separated in their own user space an addon domain will not be a different user on the system; so all sites will be vulnerable when only 1 of the domains was hacked due in example an outdated plugin.
– Not easy to move an addon domain to its own ‘account’ (at least in cPanel environments)
– No SSL for addon domains possible, only for the main domain (in cPanel environments)
Alternatives for hosting many domains
Of course you could just buy an hosting package for each domain you want to host, but each account would have its own cPanel and this may be a bit harder to manage.
But another option, this may sound silly to some, Â is a reseller account; it allows you to add unlimited accounts (and thus domains) which each have their own resources, and if the hosting provider did have a good security setup they would also be correctly separated from each other. Also each ‘account’ would have an option to setup SSL certificates.
Also in case of a reseller account your ‘accounts’ can be quickly moved to other packages or even their own server if they grow larger; something which is very hard to do with an addon domain.
Recap
Addon domains are great, unlimited or even limited, if you need a cheap way to host a second domain on your account without additional costs, but if security and speed are important to all your domains you should really consider a reseller account.
