Good postys usually cause a very drastic increase in traffic and business. Read more details about it. The only danger there is that the increases can be more suddenly than expected. If the web hosting is inadequate and you get kicked out on a Friday of a long Weekend, that can cause a lot of suspicion on the web. Equally bad is running out of goods to ship.
Effective traffic is targeted or selected traffic.
A posty site with a specific topic efficiently sorts out the people that are interested in what you want to show. Repeat Traffic Repeat traffic is necessary. Most marketers state that a concept or product needs to be exposed an average of seven times before it is bought. Luring anyone onto a site ONCE with a freebie is therefore not very effective. That does not mean you should throw out what worked today.