The main page http://www.physicsoverflow.org/ should _not_ come up with ''Recent activity in Q&A'' as now, but instead with
- (left half top) an inviting summary of what PO is,
- (right half top) a questionnaire asking for the most important user preferences (namely ''I am interested in [menu of categories and/or representative tags]'') where one or more could be marked,
- buttons "search'' and ''invitation to register'', and
- a button ''view'', which upon clicking gives (on the same page but below the top) to new readers the questions with highest number of votes and/or highest answer quality (and a menu to switch to different modes) on the interests selected before.
Readers with an account should be able to customize in their profile their preferences about how the main page appears.
Justification:
When visiting a site, I first want to see what is interesting about it (else I leave it) before I am interested in the current traffic. For example, in Wikipedia, who wants to know which entries have been changed most recently? Only the dedicated workers. Everyone else wants to be able to choose a topic of interest.
The content is there upon an additional click, but which content to view should not be left to the accidents of the day. If one wants an inviting general purpose content, one should select from each of a set of representative tags (the ones which are specified in the menu for defining the interest) the one or two best-answered questions. These could be listed next to the menu of tags. to illustrate these. (The list of all tags is useless and should not be visible directly.)