From all I've read, 13 sites is WAY too little to base anything on.
I've just started to submit free sites myself and they're coming out slowly at this point.. but I'm putting most time into learning and setting up an infrastructure with recips/sponsors/templates etc. that will (hopefully) allow me to submit at a much quicker phase and with less effort when it's all done.
But I'm not counting on any real results until I have at least 100 sites out there for the SEs to chew on..
I'm focusing on free sites for now... once I have that down, I'll try other things too.
It sure is discouraging to look at the stats right now though
Just my 2c.