Google's priority inbox: a dream or a nightmare?

It appears that these in-built filters take how you respond to emails into account, iteratively fine-tuning how future incoming mail is handled.

On the other side of the fence are the email marketers, for whom this is potentially a nightmare. With this kind of filtering, they're going to have to work extra hard to capture the recipients' attention.

Email marketing messages are going to have to become extra-relevant, and basing them on behavioural data, such as previous interactions with the recipient (e.g. purchase histories) will help hugely with this. In this context, eCRM is going to become more and more important - ensuring that the marketing messages that reach customers are welcome, useful and appropriate to the recipients' interests.