When starting your first WordPress website, most people would opt for shared hosting.
But when you begin creating additional sites, staying with shared hosting may not be the best option.
All your websites are created under the same account. With multiple sites, this can become unwieldy and confusing to manage.
Your first website’s files will be directly under the public_html folder, and any additional sites (usually called Addon Domains in cPanel) are placed into that same public_html as well.
So in the event that one of your sites gets malware or is hacked, the infection can easily spread to every other site in the account.
In reseller hosting, however, all your sites are created as separate accounts which provides for complete isolation between one account and another.
This is further enhanced if your web host utilises CloudLinux (most webhosts do). CloudLinux has a feature which creates a secure cage for each individual account to prevent cross-contamination.
So if you plan on hosting multiple WordPress sites, reseller hosting is the better option from a security perspective.
Costs and Expectations
Shared hosting is invariably cheaper than reseller hosting, that’s true, and seem to offer just as much, if not more, resources. But things aren’t always that clear cut.
Some web hosts will offer very large limits (sometimes even unlimited) for shared hosting. This is of course simply a marketing gimmick, as unlimited hosting is not actually unlimited once you look into the finer details. There are no infinite hard drives. They will generally limit the number of files, the resources you can utilize, or place other restrictions.
Therefore, reseller hosting is a lot more realistic in terms of what you can actually use. They usually have clearer set limits which won’t leave you guessing.
For example, Hostgator’s shared plan offers what they call, unmetered diskspace.
But once you click for further details, there are actually limits.
Looking at their Reseller Hosting however, you can see that the diskspace limits are clearly defined.
[screenshots taken Nov 29 2018]
With reseller hosting, you know exactly what you are getting.
This may be a pro or con, depending on your perspective.
Using shared hosting, because all your sites are under the one account, you only need a single login for your control panel (eg. cPanel) and FTP. This can be convenient if you are the only person accessing your websites.
With reseller hosting, each website has its own separate cPanel. This can be useful if you need to give someone else (such as a web designer, a friend or colleague etc) access to one of your sites, but not the rest.
Reseller hosting comes with an additional interface called WHM. You will need to use WHM to create a cPanel account for each website that you plan to host.
It is mostly straight-forward, but you should allow an hour to familiarise yourself with how to setup and use WHM. This may put some people off, due to the increased complexity vs shared hosting.
A good guide for how to use WHM is this tutorial from SiteGround.