what articles are the best sell on DP?

lets say i will make 100 unique articles, then sell on dp for $1000, what great niche would that be? or can i make random?

Now a days SEO is a rocker

also dp likes cheap stuff so I don't think you can make that amount with 100 articles. What you can do though is make 5 PLR packs and sell them for $10 each that is $.50/article. Sell 15 packs each and make money.

1 PLR to 15 people at $10 = $150
5 PLR packs = $150 X 5 = $750