bwnbwn - 2:32 pm on May 14, 2012 (gmt 0) [edited by: bwnbwn at 2:38 pm (utc) on May 14, 2012]
Here is a pretty good list to help you determine if your pages are considerd thin. Note just a help list nothing is absolute.
1. Poor grammar and spelling errors
2. Content Too short
3. Too long repeating the same stuff boring content.
4. Too vague working around the topic but providing nothing for the user.
5. Duplicate Internal pages
6. Duplicate pages on cross sites you own or manage.
7. High number of ads be it adsense, banners for paying clients, affilates etc.
8- Make sure if you have a search fuction your not creating duplicate pages with diferent url's from the search.
9- Overoptimized pages targeting a specific search. The content is written for a specific search and the term is used in the text title h1 h2 and so forth in a manner that would draw this type of filter.
Thin can be 10 words or 1000 words there really isn't a true defination of thin. You could have great content and just got carried away with the term your trying to rank for. I see this more and more being an issue.
Sometimes it is better to say more using less. Internet people (me included) are scanners write for that type of activity. I have learned the more you say in less words tend to get the most attention IMO, but should be written in a manner that makes sense, grammer is correct, and provides a solution or value to the term searched.
[edited by: bwnbwn at 2:38 pm (utc) on May 14, 2012]