Well, I hear sellers on this forum say to get out there on Facebook and Twitter . I've checked out the FB pages of some super-busy sellers, and yes they are on there daily, posting their new items, also coupons, raffles, giveaways...it's alot of work but clearly it can pay off.
Other than deliberate self-promotion, there's an element of luck....Etsy picks hot items to post on the front page, and on the emails it sends out. Seems to get that kind of attention your best bet is to have fabulous photos and innovative items. Price is not relevant.
Then of course there are sellers making lots of transactions selling underpriced items, offered in huge quantity, identical to other Etsy sellers....that look mass-produced.....especially in jewelery....