You're right to avoid email spam -- not only is it frowned upon, but it could fall afoul of the FTC CAN-SPAM rules. I was referring more to getting included in established email newsletters (not dedicated email blasts). For example, your industry might have a weekly newsletter targeting the things you are interested in. See if you can get included in that (for free, optimally), or take out a low-cost text or other ad in the newsletter. They usually go out to already qualified, opt-in audiences and have a better response rate than other forms of advertising.