Search partners are search engines that syndicate Google's AdWords ads. These websites aren't large enough to build their own ad serving platform, and don't have enough users to attract advertisers to it.
Without wanting to sound overly harsh: if you had an extra hour to spend on your pay-per-click (PPC) advertising, would you use it building an Ask.com campaign or optimizing Google? There's no contest.
Too Many Search Partners!
The search partner network is blind. That means that you can't see in advance which sites your ads will run on, you can't see performance per site when your ads are running, and you can't remove poorly performing sites from your campaigns.
That's bad, and it's wildly different from what we expect in the rest of AdWords, where transparency and control are the orders of the day.
Why is it a Problem?
The search partner network is not terrible. Not by a long shot. Although you can expect lower click-through rates (CTRs) than you'd get on Google, you may well find your CPA to be as good as Google, sometimes better.
But not every site will work well, and it's tricky to know how to optimize it. Tricky, but not impossible.
Step 1: Learn
Using Google Analytics you can easily track your traffic from search partners, site by site. This data is neither perfect nor easily actionable, but the more you know...
Set up this Google Analytics filter to get a profile that will tell you exactly what traffic is coming from which search partner.
Depending what kind of website you're running, you may be surprised at the results. There are websites in the search partner network that are not search engines.
Take a look at any popular Amazon product page. What you'll see is a selection of links somewhere in the middle, titled "Customers Viewing This Page May Be Interested in These Sponsored Links." These are AdWords Search Partner ads.
"But wait," I can hear you shout. "There is no search query on this page!"
You're right. Sneaky devils. They're taking the product name (which is likely to be some long title including a short description and maybe a product code) and sending that to Google as a search query. If your keywords are in phrase or broad match, and include part of that product title, you could be in trouble.
You'll see a keyword that usually gets 2,000 impressions per day suddenly shoot to 20,000 impressions in a day. That's not a surge in search activity, that's Amazon.
Other major sites are in this network too: eBay and Gumtree (in the UK) spring to mind. Each of these can have an enormous impact on your campaign.
Step 2: Act
First of all you need to see how much of a force in your campaigns the search partner network is. To do this keyword by keyword you'll need to use the "Top vs Other" segment.
If you identify keywords with crazy search volumes from the search partner network, you've got to discover why.
Check your search query reports for that keyword. What you might see is some ridiculous unlikely search query that gets loads of traffic.
These situations are common, and need common sense applied by the campaign manager. If you see a search query which doesn't seem likely to be that popular, it's probably not. It could be a product name, or a page title, or a navigation breadcrumb. You'll see all of these and more sent to Google as search queries.
One simple rule of thumb applies when taking action: if it looks ridiculous, it's ridiculous. Stop it.
Use exact match negatives to block specific instances of your ads appearing on the search partner network.
How Much Work is This?
I won't lie, proper management of the search partner network isn't trivial. Nor should it be. By removing almost all control Google has tricked us into thinking it doesn't need monitoring or management. But now that we have these tools at our disposal, we should use them.
Perform regular checks of your search query reports looking for ridiculousness, and cut those from your campaign. Your account will thank you for it.
Yahoo & Bing
These aren't Google search partners (although in the UK their traffic is low enough that they might as well be) but they have just introduced a similar problem: two networks, no control between them. You need to be able to make sure that your Google Analytics can track them correctly.
Follow these tips about Yahoo and Bing tracking, and try to keep an eye on which portions of traffic come from which search engine. If you get keywords behaving differently from one to the other, you've got a proxy for actual control.
Turn the keywords up or down that get traffic from one site rather than the other. This will give you back some performance.