The numbers on concert tickets

I have been to serveral concerts in Japan.
The tickets got numbers like this;

A234
B12
C72

and so on.I was wondering if there is a difference with the numbers if you buy them at the lawson or at family market or seven elefen?

Because untill now I always got them at the Lawson but I allways get one of the last numbers even when the ticket sale just started.

Is there a diference between the stores?

No real difference though some people will say they have better luck with some ticket services over others.

A lot of the time, before the general sales start, there will have been fanclub tickets, presale tickets and possibly even other pre-general sales tickets for sale. So by the time the general sales starts there might not be many tickets left. And you have to be fast if you want a ticket at all for a hot gig.

But then again, you can sometimes get lucky and get a really good seat on gensales, too.