Comment 14 for bug 956618

This sort order is not going to work effectively across all the different ways that people are searching for others. One type of use requires the nickname is more important and the other type requires first or family names.

The real goal here is that when a user types 'wil' into the auto-complete for the first time we show all the possible matches on different (and relevant) fields for that term. When the user selects the desired person from the auto-complete list Thunderbird associates the term 'wil' with that person.

This idea is called 'frecency', by the Firefox team, which was built into the FF3 awesomebar auto-completion. It gives the user a sense of the application learning their habits and allows them to find the same person by the same string over and over again.

We need to have a similar algorithm to this built against our contact database. I believe Gloda already has an idea of 'frecency' built into it, however we need to keep tweaking the data points it uses.

https://developer.mozilla.org/En/The_Places_frecency_algorithm

We should probably open a new bug for a frecency index and I recommend against this path.