RhinoFish - 7:06 pm on Sep 29, 2012 (gmt 0)
search partners often outperforms on ROAS, but does vary (note, we're in north america - your uk situation will be different). try the conversion optimizer, it allows for these differences, your sp cpc's will be lower - allowing you to nest the sp traffic in with the non-sp.
add more negs and test more ads to improve ctr, you need a higher uptake volume overall to justify this work. consider segmenting your current ad groups furth, to improve CTR (bolding), and to allow greater use of the conversion optimizer ad group CPA bids.
for CO, use target cpa, not max cpa.