I collect resources like this on my niche marketing blog and have a ton of them.
Here's a few I just searched for and pulled up for you.
NOTE: You asked for hottest SELLING - many of these are "most popular searches" which is what people are interested in, but still good for finding hot niches or new products to promote.
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Some of the best tools for finding hot trends and niche brainstorming including Google Hot Trends, eBay Pulse, Yahoo Buzz and others.
Rand over at SEOmoz has created a VERY cool resource that searches and displays the most popular searches, key phrases and products from all the above resources and others, to help you discover rising trends and buzz worthy new niches all in one place.
SEOmoz Popular Searches is free to use right now, with no sign-up or nag screens. It even lets you download the list as a CSV file to save and use later or massage with your favorite key word tool.
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Google just released a PRETTY cool tool affiliates may find useful.
Google Checkout Trends shows sales/revenue volume for actual products that were sold through Google Checkout. So instead of only knowing what products were searched for, you can see what products were actually SOLD and view product comparison data or seasonal buying trends.
Here are the results for
wii VS xbox VS playstation. Take it for a spin and see what you think. The data can’t be 100% accurate, as it’s only Checkout merchants - but it could be representative and give affiliates some insights.
Here’s an overview from the Google Checkout blog.
New on the hot list: Google Checkout Trends
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“The Shopping.com Consumer Demand Index (CDI) makes it easy for you to put your finger on the pulse of consumer demand. With millions of shopping searches conducted each week, the CDI reveals emerging trends and hidden gems while highlighting the hottest products.”
Check out TONS of different product categories.
PICK a category and drill down to view the top 100 searches which are updated every two weeks.
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Ebay Pulse - What’s hot and most searched. Drill down DEEP by category to find sub-niches
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Ebay Want It Now - They want it NOW! - Dig DEEP by category
Happy niche hunting!