Pros and cons of separate hosting accounts versus using an addon domain

Question

For historical reasons, I have "Site A" on "Hosting Account A", and "Site B" on "Account B", totally independent accounts with the same vendor, Bluehost. Both are primary domains. Now that Hosting Account B is just about to expire, I'm considering letting it disappear and moving Site B to an addon domain on "Account A".

Both sites are non-commercial, narrow-interest, very-low-traffic, hundreds of page views per month. The file weights for the sites are non-trivial, especially as I like to install specialized CMSs in subdomains. Since Bluehost allows unlimited hosting space there should be no issue with the file load, except I've seen hints of an issue with total file count, maybe 50k files -- which I'm not currently close to hitting, but might eventually.

My question: what are the pros and cons of using separate accounts versus hosting Site B as an addon domain?

Obviously, using a single account is cheaper by half, and I know that my authoring environment (DreamWeaver CS5) complains when it detects nested source trees, telling me "Synchronization" might fail in such cases, but I don't depend on this feature.

What other factors should I consider?

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Added in response to PatomaS:

Thanks for your comments.

Site A and Site B are currently running custom-built php-driven code, no CMS and no DB associated with either. These sites do require some simple .htacess manipulations. A bit more work keeps those remappings from being applied to the subdomains, but that's under control.

When I install a CMS in a subdomain, I'm careful to use a completely independent DB for it. I just don't seem to have problems with CMS operation in subdomains.

SEO isn't really an issue: the primary domains contain totally noncommercial sites. In practice, I use CMS's in subdomain for non-public purposes, releasing the URL only to interested parties,

Switching over Site B to an Add-on Domain of Account A: I'd like any switchover to occur with a minimum gap, but with only a few visitors a month, it seems unlikely that even a 24-hour switchover downtime will be noticed by anyone. After that switchover, Site B should appear at its previous URL and operate exactly the same as before, so I'm not sure about what issues you anticipate.

Other than the htaccess issue referenced above, and the problem Dreamweaver has handling nested site directories I mentioned in my original post, I'm not seeing anything really difficult internally. You say, "...there is going to be one site..." but as far as I can see, from the point of view of the outer world, Site B hosted in an Add-on Domain on Hosting Account A looks totally like it did before, when hosted in a separate account. What am I missing?

Answer 1

The only real advantage is saving money, all the rest are problems, or potential problems.

Let say you have already a CMS working in Site A, and you are completely familiar with it, one you add the same CMS under the first one, you are using it in a way it was not designed from the beginning, so you may start having problems with .htaccess, permissions, error reporting, plugins, etc.

Obviously, if you don't know that system well enough, the potential for problems just increases.

You need different names for the tables in the database, which seems obvious, but have to remember that at the moment of setting the second one, otherwise it may be catastrophic. If you can use different DB this is not a problem, but get's closer to have different domains.

The administration scripts of many CMS are very picky with routes since they have extra layers of security, if you have already tested that in your local system then is not a problem, otherwise, you may end up with a Site B that you can not administer.

Backups are simple enough from the DB perspective. If you have one big DB for both, then you just make one backup, if you have 2 DB, you make 2. The problem comes when and if you have to restore information, many times even dumps generated and restored in the same system, let's say phpmyadmin, have problems so if you have one big DB, you may end with some extra problems.

Once you integrate all the content, there is going to be one site, so if you worry about rankings, that could be a problem considering that it may be a difference in amount of content, links, redirects, etc. If you don't mind that, then there is no problem.

From the perspective of your visitors, losing the site may be a problem and they may not find the new destination if they don't visit the disappearing one while you have the redirects in place. If you don't have returning visitors or you don't mind, that's not a problem.

One option you may have, about the cost, is getting a reseller account, with the same hosting company or another one you like, the price may be interesting and then the costs will be lower than they are now but you will still have two separate sites. You just have to look for plans that offer what you need.

Edit: Considering what you mention, if you have everything under control, with few visitors, good practices and knowledge, there is no real problem in having addon domains.