The one thing that is constant about the internet is change.
You need to make sure that your site is delivered on a platform that takes this into account.
Accessiblity Standards, Social Networking API's, Online Maping API's, Open Social, New Payment Methods, Search Engine Optimisation Techniques are all technologies that have emerged or fundamentally changed in the last few years, and the pace of change is only getting faster. You don't need to understand all these buzzwords but you should make sure you are working with someone that does!
Features that were new and expensive a few years ago now become standard functionality you cannot do without.
Ensure that your website provider has a strategy for keeping apace with change and bringing you along with them.
The software platform that your site is delivered on should be under constant development to improve and add new features, with a simple upgrade path to allow your site to continue to benefit from this development.
