First of all you should note and have stats of what your buyers are interested in buying, not every launch is going to apply to your list or web site visitors. I'm not a "hop on the latest fad, product etc." kind of person, so I certainly do not promote EVERY launch that happens. Although some people do and hey whatever floats your boat, no judgment passed. I take good care of my lists and my web sites which has built me a strong relationship with my contact base and I take good pride in that, so pushing every product that comes out is not feasible for me. If you don't have that information, it's best to start using techniques in order to obtain those stats. ie: survey's, polls, general questions sent out to your mailing lists or on your web sites and definitely use tracking tools - ie aweber etc. so you can see who and how many people are clicking what and how many are not. I also find that if you give people some type of a reward for participating, your chances of getting that key information goes up - perhaps; a free book, report, wp plugin .. something like that.