What is the most important metric when buying domains?

[newdawndomains]

I went to expireddomains.net for the first time anad looked at the massive list of domains but am having trouble figuring out which metric or metrics I should look at first to discern whether it will be worthwhile for me to buy them.

Is it how many backlinks they have? I figured this probably isn't since they could be spammy links.
Is it the domain age?
Is it the Alexa rank?
Is it how many letters it has (but only if they're real words)?
Is it the traffic? What if it's not authentic traffic or high quality?
Is it the appraisal figure given? not sure where they get this number from.

I'm new to all of this and was wondering what the experts who are in this biz look at when it comes to metrics like this.

 

[Keen]

L U C K is the ultimate metric in this game...
traffic is second imo

 

[Samer]

I personally like age,

But there can be aged garbage; so choose wisely.

Samer

 

[damance]

avg mont search
cpc
lenght
ext

 

[D Haynes]

I don't look at metrics. I buy names I like the sound of.

 

[garptrader]

A plethora of potential end users which have social media profiles with that keyword (and which possibly would be interested in acquiring the domain in the future).

 

[Isaac Meeya]

Keywords in name
Length
tlds registered esp de,org,eu,io
related domains

 

[LUP]

2 keywords are related, aged, pass radio test, suitable for brand name

thats what i like