Ive heard some good things and some bad things about purchased opt in email lists. are they actually effecient or totally worthless? also, i read in a book a good way to build email lists is to trade lists with someone that has a similar product and target consumer group as you. any body have experience with either of these things?
I would never trade lists, or buy lists for that matter. To me, it's all about building a relationship with the people on your list. Everything else is spam to me. The people on your list need to understand what they can expect from you (how many emails, what type of content etc..)
I have to agree with slymarketing, building lists is all about the relationship that you have with your users. If you go down the route of exchanging lists or buying them you will likely lose a vast amount of the users the first time you attempt to use them. They have never heard of you, they didn't subscribe to receive anything from you and they will most likely consider you as a spammer. If you find someone who has a similar product to you instead of exchanging lists why don't you talk to them about possibly promoting your similar product on their list. Let them recommend it to their users and they will likely yield a better response. You could offer them a commission on any sales in exchange.
You can see if you can add an article or an ad to other email newsletters in your industry. In that article or ad, you have to push people to your site and encourage them to opt in to your list. This is a good way to be useful and build your own list.