Finding good solo ad vendors usually takes research and patience. A vendor is simply the person who owns the email list and sells clicks from it. Many affiliates read reviews in marketing forums and check past results shared by other buyers. Vendors who show clear statistics about clicks, location of traffic, and refund policy often look more reliable. Even with a trusted seller small test campaigns are safer before buying large packages. Results can change because email lists behave differently. What names are often respected in this space?