While I searching, i found those seller testimonial that have bring over 20% sales. But when I bought the service, no leads and no sales for me. what's the problem?
It is hard to know without being able to analyze every detail. It could be the list but it also could be the ad copy or the funnel. Also you must follow up. Many people that complain about no sales are not following up. Hopefully you are capturing their email. Then you should be following up and unless you are a laborer I would recommend using an autoresponder campaign sequence to automate that process.
If you are new to email marketing there are many people here that I am sure will help you and honestly UDIMI is a great site. Sometimes all it takes is finding that matching vendor for your offer.
There are some Vendors with weak lists but as the saying goes you get what you pay for. It is really rare for me to see one of my favorite vendors at minimum price. Most of the great vendors start at $0.49/click and go up. Sometimes you get lucky going cheap but usually you are gambling unless you are already familiar with the vendor
I hope that helps. Feel free to message me. I am not a vendor I am actually a customer but I will still help.
To get conversions (leads and ultimately sales), make sure your offer is a good fit with the vendor's lists. If it is, make sure you're promoting a decent offer with a simple landing page. Simple often works best. If it's a little too complicated with a lot of content/images/flash and multiple opt-in fields, your conversion rate on the front end will drop.
Glad to help if you need any assistance - will evaluate your offer and funnel. I'm just a message away. :)
Daniel said it all!