We all agree that placing ads on Internet is an essential and important part of exposure and promotional process that is so unique to CyberSpace.
There are a great many different locations where you can place ads on Internet. Literally, there are several hundreds of thousands of such FREE Ad sites, and you can find both FREE and Fee based online publications.
We have even set up a web site that links you to almost 12,000 of more popular sites that are available with almost 100 sites detailed individually to ease posting: http://emailexchange.org/freeads.html
But before you jump into posting ads online, especially if you opt to pay for an ad, you should establish a clear-cut plan to chart your responses.
The only way to chart your responses accurately is to "Key" all ads you place, whether online or in off-line publications.
Once upon a time, simplest manner to "Key" any ad was to write, Dept. No. 1234, or whatever number/letter combination you might want to use, and this allowed you to know from where you were receiving your responses.
Whether an ad is FREE or paid for, if you know if it is drawing responses then you can make informed decisions about continuing to place ads at those particular sites or publications.
Afterall, it does not make any sense to keep posting ads in sites or publications where you never receive responses. Such an effort is a complete waste of your valuable time.
Those sites that do work for you can then become focus of your online ad campaigns.
All it takes is a working "Key" chart.
For those of you that are spending monthly fees to receive web space, email aliases, etc., solution can be as easy as setting up individual email aliases for each account or each of your different ad sites or publications.
For example, you place an ad at ABC Ads and you "Key" them as email@example.com. or firstname.lastname@example.org, etc. That is beauty of being able to control "Key".