Over-Use of Keywords
 

I recently read somewhere that over using keywords in the content of the page can have a negative affect on SEO.

For example if you had a page:

SiteX.com/dog-collars.html


Then you had Dog Collars written say 20 times in the content. What I read is that it is better to only have it around 3-4 times, plus in the H1 tags and title. Does anyone know anything about this, or if this is complete B.S.?

That's just common sense. Standard onpage SEO is not about spamming (unless you're a blackhat), it's about writing good content and integrating a few key phrases. Mentioning the exact same keyword 20 times in an article is crazy 99.9% of the time.

I understand that, but sometimes you need to use the same keyword over and over. Would that be negative?

Depends on density.
If you have a huge page covering everything about XYZ Poker
You might say XYZ poker 15 times on that page. If it is surrounded by a ton of other content where it is not spammy it shouldn't be a problem.

Thats exactly what I meant. Thanks!

You're right about having too many keywords on a page. I have heard several sources, but I believe anywhere from 2-5% is prime.

Once in a paragraph seems more than enough.

I'll write a page and throw it up, then do a little tweaking later.

I found with trial & error that over optimzing will lower your rank.

6 or 7 times in a decent sized page seems ample.