The below tips/suggestions are from my own personal experience with email submits back when I ran them.
Selecting Keywords
This is a very important as many of you should know at this point. It's not as simple as just filling up your keyword list with keywords, since sooner or later your QS will drop, and your bids will go up. Once your bids go up, your ROI will pummel. Must I mention that your QS WILL go down due to the lack of quality of poll pages. So what you must do is target high traffic keywords that you can get out within a day or two. The easiest way of locating such keywords is by reading the news. If something major happens on the news, then people will be Google'ing in the title of the news. Now, the traffic will most likely decrease and drop by the next day, but for the day that it is major, the keyword title will get a lot of searches. Not only that, but there will be no competition, so your bids can be low also. Everyday you delete the keywords from yesterday and add more based on today's date and so on. This has to be an ongoing process.
Obviously make the poll relate to the story keywords your targeting.
Selecting Offer
This is also another issue, don't promote something that has been seen everywhere already. I'm quite sure that every person on the internet has seen an ad for a free iPhone, so be more original and find a submit for a product that has been less seen. What's even better is find a niche product, like free make-up, or a free vacation; these have a much lower scrub rate.
Handling Your Campaign
This is VERY important. 95% of submits will start scrubbing you soon after you bring a dozen or so conversions. Typically this happens within 24 hours. So what you must do is rotate your submits frequently. Have 10 email submits at hand, and every 12 hours, rotate another one in, and keep repeating the cycle. This will minimize the amount of scrubbing you get on your campaign.
Landing Page
Couple members I've seen had posted their landing page, and I noticed a couple huge problems. First of all, you should not have any external links on your poll page, besides the link to your submit. Don't place any news articles that lead the visitor out of your LP, you're pretty much giving away your visitor. Another thing, make sure that the whole poll page is above the fold. The visitor should not need to scroll down the page to see anything, everything needs to be compact right in front of them. The last thing is to use a darker color outside the poll table, and a lighter color inside the poll table. A human being will always cast his attention directly to the lighter area by nature.
