Think of it in terms of customer service. Users stick around when they feel served by your site. They don't care how you manage to serve them, they just care that you serve them well. This doesn't mean that technology isn't crucial, but rather that technologies should be measured in terms of the feature set they provide. It all depends on whether it makes a difference to your users.
Convenience is far more important than flashiness.
If users don't find your site convenient, it doesn't matter how impressive it looks. Keep three elements in mind. Studies show that users do not proceed through web pages in an orderly, linear fashion. They skim, hop, and toggle among pages and even among different sites. So, easy navigability is paramount, and really good navigability will mean that users not only know where they are but can also track where they've been.