04 May 09 1:11 am
To answer your first question, you can find some trending information on products over at cbengine.com (always-clear cookies when finished using the site) I recommend using the free information they provide, and not paying!
Here is MHO on your second question. What comes first the chicken or egg? Well that age-old question applies to your question too. For me, I look at the product as the chicken, which makes it easier for me to produce the eggs---keywords.
I would assume the recommendation is based on general ease of implementation. However, I do daily keyword research based on current events and current popular searches. The research I do with a product in mind tends to lead more focused, plentiful, and productive results.
A product can have a positive impact on how I research. For example when I am researching with no particular product or niche in mind I am bound by my own personal knowledge and preconceived notions. Nothing we do happens in a vacuum, our personal limitations can get in the way.
Take Mark’s WowBlackBlook.com example: imagine I know nothing about WoW or mmorpgs and I come across the keyword phrase "wow gold farming" in a random keyword research session. Would I know where to begin with that keyword, most likely not? I would just skip over it because it would not fit into my current knowledge base or frame of reference. Looking into every keyword to see monetization potential is impossible.
In other words, sometimes a product can lead you down a path you would otherwise over look. Products can open our minds and get us thinking in new, more productive ways.
Sorry for the wordy answer, hope that makes a little sense. Just my opinion on the topic, I would be interested in hearing yours, and others, opinion on this topic as well.