A safelist is a place where ALL members can SAFELY send their ads to the other members of the safelist. These emails cannot be considered as spam because everyone has opted in and confirmed their email address to be placed on the list. It is also known as an 'optin list'. In return for you being able to send your ad to the list, they in turn are able to send their ads to you, that is the price of belonging to a safelist, If you can't 'handle' getting ads from others then please do not join the list.
Some safelists are credit-based. For each ad you read you will recieve points which are added to your account. You can accumulate points to use for posting your ads. Credit-based safelists are the most popular. Use a tracking system to
track your ads to determine which ads and lists are responsive.