About selling products on DP

Over the times everytime I needed some quick money I used to sold some crappy products at DP, make a few hundred until someone starts crying out it was a scam or the product just died.

Right now I have a somewhat different mindset, and I've been selling some really unique and good products on DP, the thing is, even some products that have some raving positive reviews and make some $300 - $500 in a week, eventually die out and just stop making money.

How do DP sellers keep a product selling long after the thread is created?

Do they create a new thread about the same product on a weekly basis or what?

I have currently some really great products selling on DP, one of those got some really superb reviews, I created it some 2 weeks ago, and it made some $2k in sales in the first week, then on the second week, it only made me like $300, and now, for over 4 days I haven't made a single sale.

Any ideas or advice on how to keep the products selling constantly without dying out in a weeks time?

Thanks

The threads usually die when someone else posts something similar cheaper. For longevity of the thread - answer all posts promptly & also ask your customers to post a review for you. It might also help if you were to start the thread of with a 'discount' for x amount of members - then offer another x amount etc. 2k in sales is good though well done