Diversity is good. Keeping your web sites – in case you have more than one – located at one web host has some risks like potential disasters taking down the host (earthquake, hurricane, flooding) and economic problems with the host (going out of business). Those risks are less likely to happen, but the one risk – or challenge – all website owners face if they own and operate more than one website is effective search engine optimization (SEO).

The advent of the search engine has created a remarkably economical method of getting customers to businesses for “free.” The traffic is free, in so far that the business does not pay for the traffic directly. However, positioning a number of websites to rank well in search engines is no accident and takes time, effort and money. When a website owner operates more than one site, there is an opportunity to increase the traffic between the sites with SEO. The SEO benefit can be confounded by hosting all the sites at one host.

Search engines – love them or hate them – are still driven by links between sites. A website linking to another website is a vote for that site. By carefully diversifying your website hosting across multiple providers, there is less chance that the search engines will feel that your network of sites are trying to “game” the system. Conservative linking – when the links are relevant and improve the visitor’s experience – between a network of sites will help improve search engine rankings, as well as organic traffic between the sites. Diversity of hosts is an important part of the effort, but search optimization needs to be balanced so as to not shine the spotlight on a network of sites and make the engines perceive the network as a purveyor of spam.

There are also times when having multiple domains at one host is a good idea. Since things like having a shared database used by multiple domains makes multiple domain hosting an obvious cost saving strategy. For every rule there is an exception, but having some diversity in web hosts is a good rule to consider for SEO as well as other more vital, but less probable issues like disasters.