I know that opinions are like elbows -- everybody has them -- but IMHO it seems that attracting buyers (purchasers, customers, the folks that pay for our goods) would be the way to go. If sales are good across the board it seems a no brainer that sellers would find out/hear about (it's like gossip -- it's like wildfire) FLOCK to the watering hole.
Which would enlarge the site.
Which (hopefully) would bring more customers.
If I tell two friends, and they tell two friends, and they tell two friends, etc., etc.,