Splitting a store from a website

Recently a client brought in an interesting request to split their store off onto a subdomain, for example https://store.mywebsite.com. There are both advantages and disadvantages to this idea. I thought I’d share those insights with my audience.

Pros

1. The plugin load gets split, so each site runs less plugins or customization risks above the core software baseline.
2. The traffic load gets split amongst website environments, especially the more processor intensive eCommerce traffic from the greater blog traffic.
3. With separate Databases and Media Libraries each site can grow further before hitting any size limits or long queries. The administrative interfaces are also more manageable since your comments, media files, etc., are separated.
4. The business looks bigger having two URLs with two separate home pages.
5. Navigation and layout can be more optimized for the context, but keep the transition easy for users to follow.

Neutrals

1. This is only worth considering when eCommerce is NOT the primary function of the traffic on a website, to make the split meaningful.
2. This provides an option to use a separate web host, but this can be a con if it means paying additional fees above what a combined site costs.
3. Users can exist on one site and not on another, which is a pro for security but a con for shared access.

Cons

1. Merging the sites back together would be very difficult. Consider where post IDs conflict. For example Order ID or Product ID 5555 on one site would conflict with blog Post ID 5555 on another site. Combining sites would involve resetting post IDs within the myriad child tables. Most exporting and importing approaches would disconnect order histories from products. There may also be problems with overlapping URL slugs (for example between product categories and blog categories).
2. Users won’t have single-sign-on between sites without some considerable efforts. To have shared access one would have to utilize global cookies or an authentication token toss between sites that syncs new and existing user accounts as well. Then you’ll be backing up multiple copies of essentially the same data.
3. Site search and widgets with post counters won’t cross between sites. One would have to set-up RSS widgets or API calls to power those widgets.
4. If the sites run separate themes they won’t match. If you are trying to match same themes with headers and footers, anytime theme settings, widgets, or menus change you’ll have two sites to keep in sync.
5. A separate SSL certificate will be needed, if not already auto generated by the host using LetsEncrypt or CloudFlare. If you’ve already purchased an extended SSL certificate you may need another one for the new domain or subdomain.