I spent most of my time doing E-How articles for them. I didn't concentrate so much on impressing the editors as I did focusing on making sure the content was something the reader could follow. If you concentrate at first on writing what you know you should be fine. Take a look at the guidelines and listen to the editors if you get a rewrite and it's easy money. By the end of my 2nd month I was making about $600 a month for writing 5 articles a day on Saturday and Sunday.
Really want to do 100 or so revenue sharing articles but want to do a lot of research on some good keywords to generate page views so trying to gear myself up for that.
Demand Studios does pay twice a week. What you were probably experiencing were cut-offs. like if a pay is tuesday and u finish an article on monday, you wont get paid for that till friday because the cutoff for tuesday pay is sunday night.