Here's a simple tip for a traffic spike: Make sure you register your site with the BING Webmaster Center.
Here's why: There's a lot less competition for Bing keyword ranking compared to the market leader, Google. With Bing, you can still get some great keyword traffic for words that are extremely competitive over on Google.
Here are a couple of real world examples over the last month:
FdicLimit.com - This domain got 132 organic visits from Bing, but only 32 from Google.
HolidayDoorbuster.com - 252 organic visits (Bing) , 81 (Yahoo), 25 (Google).
You can see that Bing is generating much better traffic for these two sites. The only explanation I can see is that Bing users are more likely to click on ads, than users of other search engines.
Try Bing with your keyword domains. It's worth the effort.
Happy Domain Hunting!