Another newbie frustrated with ads

[arrrtiiichhhoak]

Hi.  I've been running Facebook ads over the past few weeks for my print on demand store.  I'm getting 1-3 sales on days when ads run, but am getting frustrated when I try to optimize.

The first item is a t-shirt aimed at artists and passionate people that work hard for creative rewards.  It sells 1-3 items per day when the ad works.  I targeted it toward people that like visual arts or performing  arts and must like groupon.  But when I try to alter the ad in any way, it just stops.  I ad more interests to target, keeping the audience between 1-5 million.  But then the ad stops showing.  I switch from "view content" to "purchase" for a day and the ad showed all day with only 11 clicks, no sales.  How do I optimize and ensure it keeps showing in people's feeds?  

I also have a pair of leggings that was getting about 50 clicks a day for the first 3 or 4 days, but no sales or add to carts.  Yesterday, I re-tooled the ad and it got 90 clicks today.  The copy offers 20% off coupon and stresses that this is limited edition; the landing page does the same.  I setup a retargeting campaign for it, with about 300 visits to retarget, but FB hasn't shown it once.  I'm taking the clicks to mean people like them.  They are also the most favorited item on my Etsy shop.  

Both of these ads are running at $10/day, though Ive played with that from day to day.  Both are are set to Conversions: View Content.  Changing to purchase kills em.  Ive watched a lot of YouTube videos and read posts and interviews.  Consistently,  I'm seeing advice to have CBO off, set conversions to purchase, and optimize, optimize, optimize.  But I'm not quite getting it when optimizing or-targeting results in the ad not being shown.  

I'm working on the landing pages too.  I'm trying to stress the urgency a bit, though not too much, offering free shipping, etc....