Since the US is going through an interesting time with election primaries I made sure my promos did not conflict with any election or public holiday. Without any further ado, here are my results:
9 April: Digital Book Spot. Cost: $10.50. Result: 4 sales.
16 April: Awesome Gang. Cost: $10. Result: 0 sales.
18 April: Bargain eBook Hunter. Cost: $22.50. Result: 1 sale.
20 April: Betty Book Freak. Cost: $15. Result: 3 sales.
1 May: Bookscream. Cost: $3. Result: 0 sales.
3 May: Discount Book Man. Cost: $10. Result: 0 sales.
6 May: eReader Cafe. Cost: $35. Result: 13 sales.
9 May: Lovely Books. Cost: $15. Result: 1 sale.
11 May: Read Cheaply. Cost: Free. Result: 2 sales.
16 May: Book Gorilla. Cost: $50. Result: 30 sales.
Overall, it cost $171 to run that leg of the promo. I sold 54 books. I'm not all that disappointed, since this is one of those trial-by-fire situations that everyone has to suffer through before getting any traction, and it's definitely useful to know which site works for me and which doesn't. I'm willing to try most of them again later in the year, but only with more reviews under my belt.
Updated: after speaking to Vinny at Awesome Gang he gave me an additional push on twitter and pinterest. Got 2 sales, so thanks to him!