Well I can tell you what's important from my perspective.

I've been playing with my wife (*heh* and even gigging) for 5 years now in a covers situation (I come from an originals band first 3 piece, then anywhere from 5-7 piece) and have settled into a "routine" (I mean that in a good way) of duo cover work.

I do not have to do OMB stuff.
We do not have to work with groups or any other musos at any time.
I do this and make a great living.

I fully realise the situation might be different here (in Australia) then in other parts of the world.

But to cut my overly long post short - I've found 2 things tend to get us more gigs than we can handle.

1. GREAT VOCAL ABILITY - (singing).
2. PERSONALITY.

People listen to vocals first - I'm sorry but they do, in almost ANY genre I can think of (unless, obviously you're doing Classical or Jazz improv with no vocals) PEOPLE WANT TO HEAR A KNOCK OUT - COMITTED - VOICE.

They ALSO want to hear someone who can speak on the mike - connect with the audience - do the odd joke - show something of themselves - interact with their partner onstage - ANYTHING that keeps the show MOVING - not long gaps (or even short gaps) of silence between songs.

It really is as simple as that.

P.S. Flexibility is probably a close third I should add - be able to play at LEAST a couple of songs from most EVERY genre.

We have 16 gigs this month (which is plenty for us - most of the clubs we play pay quite well and we only need a few gigs a week to be VERY comfortable), granted, it's the silly season, but next year is already almost fully booked until June.

Check out This month....
www.chi-chi.com.au