Feeling helpful today and you asked good questions. I'll try to give good answers.
I don't know US traffic very well, but abroad, .1% CTR ads get scrapped, I'm shooting for .2%-.3% or it's not worth it.
Generally, for me, it goes something like this --
1) FB suggests ridiculous price (only $1.83-$3.95 per click!) and I create my ad at bid .01 (so when they approve, I don't get a flood of traffic until I want it)
2) When I'm ready to start traffic, I start bidding about 40% of their ridiculous quote. My budget is high enough that I can spend ~20 clicks per ad at this bid. (Since traffic is distributed throughout the day, if I want to spend up to $50 at noon, I set my budget to $100. At these ridiculous bids, I should spend $50 nearly instantly. POOF!)
3) Watch for ~20m. On each creative, when it hits 15-20 clicks, I start dropping the bids. If I know my target bid price (e.g. you have bought ads in this demo, and you know you can get traffic with a $.10 bid), I drop to this immediately; if I don't, I bid .01 so that my other creatives get impressions, and follow the steps below to find my target bid price.
important Ignore the high numbers in the CPCs column on facebook reports today, they are weighted with outliers from our initial $50 spend.
If you don't know your target bid, you can find it in ~1 day of careful tinkering; Say you want to spend $250 per day, and you have a new batch of ads that got 20 clicks each at $.75c. You've pruned the .1% CTR ads, and have a few potential winners left over. Your campaign budget is currently set to $100, and it's noon, so you've spent about $50.
First, lower your bids 75% to about $.25, then up your budget to $120. We're gonna see if we spend another $10 (half the budget increase; because it is noon), or if we get no traffic.
Go play with your dick for an hour.
If you haven't spent another $10-$12 by 1pm, the volume is not satisfactory. Adjust your bids upwards, then set your campaign budget high enough to burn another $10 in the next hour.
If you have spent $10-12, you're still getting volume at that price. Drop your bids, up your budget, leave it for an hour and don't check it.
Keep adjusting your bids, then upping your budget; the goal is to have your spend equal to ($budget * hour_of_day / 24), roughly (it's not precise), and you're spending in $10 increments to find it. You can do this about 10 more times before midnight, but it's always gone quickly for me. By the end, I'll have spent $250 today, and probably lost some money in testing, but I now know that a) I can spend $.xx for a click on a .2 CTR ad, and b) my best creatives are X, Y and Z, and I can get clicks for (30/50/90)% cheaper on them, and c) tomorrow, I'll get easily twice as may clicks for the same price, make twice as many sales, and if the traffic stays strong, I can probably keep dropping my bids until I again fall short of my target budget.
Whew, hope that helps.
