I've bought yarn from ESK on and off starting in 2010 when I first learned of the "mad"ness that is Madeline Tosh yarn. Back then, finding a good supply of the various colorways in MadTosh was challenging and ESK most certainly had one of, if not THE largest, selections. One year, I made it into the 10k club, after which I became a lifetime member, which means: I have special access to sales announcements, can log on one hour earlier for Black Friday, and just recently the Sunday Stash (one yarn, offered at an extra 15% discount).
ESK continues to be one of my favorite online LYSs. From the speedy shipping, to the added bonus of the Yarnathon, to the wonderful Yarn Lotto tickets (one is included in each order and you can win up to $100 store credit, among other things) - it's truly a fun, although virtual (for me, in California), LYS. I've won a $50 store credit, and just recently $20. Quite often, I picked up $5 store credits here and there, which I saved and sent in together. (You do have to physically send in the tickets to redeem them.)
This is the second year that the Yarnathon has assigned me to a team. First year, I was a Stitchosaur and this year, I'm a Fleecy Fox. Last year, I didn't participate. I started on one of the KALs (New to you), but just lost interest. This year, I followed along for a bit and answered most of the weekly trivia questions (which earn you 50 yards per question, 10 questions per quarter) and then really found myself drawn to earning the badges - especially to reach the silver level and earn the tote bag. Once I saw the tote bag prize, I found myself obsessed with it! So, rather late in the year, I'm now throwing most (if not all) of my knitting effort into EARNING SILVER!
Best of all, even if you are cutting back on buying yarn, you can still have fun in the Yarnathon and help out your team - so there's something for everyone, no matter what stage of yarn acquisition you're in. (Note: the team assignments are random.)