Kay,
I haven't experienced a slowdown of sales in my shop and I attribute that to "working my shop". By that I mean moving words around in my titles or changing tags or rearranging items in my shop (which I really need to do again). I like to watch my stats to see what my customers are putting in search and look at what items it took them to. Then I adjust my titles to get more of my items found with those word searches. Of course, listing and renewing items is another good way and only costs 20 cents.
Blessings to you,
<3 Jewel