Every Niche no matter how Small has Long Tails

The key to internet marketing is either quality(backlinks) or quantity(ranking for long tails).  If you're into quantity(also a part of critical mass marketing) then you need to find very low competition long tails so you don't have to rank with very many backlinks.  Even then you still might find yourself struggling to rank against authority sites like Wikipedia.  You can alleviate against this by posting your articles on sites with built in authority like hubpages and by social bookmarking your articles.

Some niches are easier to write for than others for example Internet Marketing as everyone who owns a website or a blog is an Internet Marketer with their website as the product.  Every time you write for your website or blog or you do promotion for your website you are researching internet marketing.  This makes content for internet marketing very easy to churn out.  Despite the fact that it is a very high competition niche, it is still worth it to write about internet marketing as a way to find link juice to your other blogs(much as Darren Rowse does with Problogger to digital photography school) and as a learning tool for yourself(writing about a subject is the best way to learn about it).

It is so easy to write about internet marketing that you can get tempted to write about internet marketing to the exclusion of all else.  That's why I try to limit the internet marketing articles to other articles on a one to one ratio.  Even in a highly competitive niche like IM(or Make Money Online or Search Engine Optimization) there are still opportunities to rank for long tails.

There are new Internet Marketing products coming out all the time.  You can write long tail posts about this product.  "Is product x a scam?  Reviews of Product X? etc."  Even if you only get one search a year for a particular keyword that's still one person of targeted traffic and it's easier to make money with targeted traffic then untargeted traffic.  The way that people make inquiries about a product stays about the same no matter how big or small the niche is.

Same with another competitive niche like weight/fat loss.  There are new products all the time and each of these products has all the same semantic terms that all the old products did.  There are also several semantic variations: weight/fat/adipose tissue/adipocytes.  Even for specific parts of the body: muffin tops/love handles/abdominal fat/belly fat/fat gut.  This gives you a lot of potential long tails to work with.

Dogs and cats are competitive niches but there are animals too.  You can use the Google keyword tool for dogs and cats for other animals.  Do porcupines love?  How do I get my chameleon to do tricks?  Tips for grooming my pet raccoon.

Finance is another highly competitive niche.  But there are new mutual funds and stocks coming out all the time.  And, you know investors are supposed to research their investments.  That's a whole new string of long tails.

The key to quantity internet marketing is long tail traffic but the problem is that keyword tools can't come up with them.  That's why you use keyword research tools for larger niches and apply them to smaller ones.