hi just an update on my ebay store. I think that if you have an item that is not so popular (difficult to find) and you have it in your store it will come up in the search. so this may be helpful. but you also need to have plenty of stock in the regular listings so they check out your store.
I have had folks buy from auction format and then add items from my store.
Would I say a store is they way to go? still not sure but I think it has helped. but I have many hard to find items...
good luck!
http://www.stores.ebay.com/gitasan
Happy Holidays!