Having been playing around with the SCT for a few weeks, I've learned a few things. These things aren't 100% for certain, of course, but as much as I've been toying with things, I think these are mostly accurate.
Please keep in mind that it's not a good idea to get a ton of Comenity cards, as eventually they will probably shut you down if you get too many, especially if your limits rise very high and you never use the cards, or if you apply or one of their VISA or MC later. 3-5 is probably more than enough of these, so decide which ones you want most. I'm wanting Overstock most, so I'm avoiding apping for anymore so I can get that one later.
First, some cards have a higher credit requirement than others. For example, Victoria's Secret, Simply Be, JD Williams, Boscov's and J Crew all popped for either my husband, myself, or both with very low scores. However, the cards we really want most such as Overstock, HSN, and Wayfair won't pop no matter what we try. But Overstock popped on the first try for our son whose score is in the low 700s. I believe these sites have higher requirements than the ones we did get.
My husband was able to get VS to pop on the first try, but it took me WEEKS. I finally figured out this particular site wanted me to use my maiden name and an address from over THREE YEARS ago. Three years! But when I used my old address and old phone number along with my maiden name and a brand new email address, BOOM! It popped up. Later, I could not get the pop up to come back with that information, so I did guest checkout again with the exact same information and another completely different email address, and it worked! I duplicated this three times, and it happened exactly the same every time. Using the same info with the same email never worked, but once using a new one it did. Every time.
So try old names, addresses, and telephone numbers, and use a brand new email address every single time, because it seems that once it's popped for a particular email address, it isn't likely to pop again.
I haven't yet tried this by registering, in which case it's possible it could pop again on later logins. I simply used guest checkout.
So, if you're having trouble, try:
1. Use Chrome or Firefox in incognito mode, with a new session every time you try again with the same store, OR if you try with a different store. (Shut down Chrome or Firefox completely, then re-open a new incognito session.)
2. Always use a different email address. Create a new one at Gmail or Hotmail every time. It's a pain, but unfortunately it seems to be the only way to try again once you've entered an email address. I haven't tested this with a login, however. I may try signing up and seeing what happens, with yet another email address but this time creating an account.
3. Try using names, mailing addresses and phone numbers from years ago. (You will have to talk to them later to explain you used the wrong address when you signed up, and ask them to fix it for you. Just tell them your browser automatically entered your old address and you didn't realize it until after you submitted your application. Speak to a supervisor, because the regular support employees will tell you they don't have access to your information.)
Hopefully this will help some people who haven't been able to get the SCT to work for them. Use it responsibly. 
Hmm, I got approved through the SCT with Overstock (bleck) and no pop ups for J Crew, with whom I'd much rather have a card with.
My OS card will be closing soon.
My OS card will be closing soon.
Wow, 12 in a month, i shudder to think what would have happened had it been Barclays
Lesson with Comenity if you are gonna go for Comenity cards, dont overdue it with SCT cards and watch your inqs count as they will sp your account.
Lesson with Comenity if you are gonna go for Comenity cards, dont overdue it with SCT cards and watch your inqs count as they will sp your account.