Feedback is voluntary.

Do not ask for it, or make contact with the intention to solicit it. It will come in time. There really is no rhyme nor reason for how, when or why people leave feedback. They just do it when they want to.

You already know if they are unhappy with their purchase, cos my guess is, if they weren't they would have contacted you.

I remember one seller of DVD's had a lot of feedback based on the actual movie - the feedback were largely movie reviews, rather than product rweviews, so if they didn't like the movie they gave the seller a negative and wrote their comment based on the actual movie!

If you want to increase your selling limits, you could think about combining patience with trying a few things.

1) Call eBay, and draw their attention to your existing account, presuming it is in good standing and has a good track record, they may "connect' the reputation of the two accounts and allow you higher selling limits on your new account. (They did with mine).

2) Have you put a credit card on file? I think this helps to raise selling limits.

3) If your other account is already established and has good feedback and higher limits, why not consider making that your store, if you are in a hurry?

4) create another selling account. whilst this means your feedback gets spread around and doesn't reflect your true expertise (a down side) each account does allow you to list up to 40 free items a month