When it comes to lead generation, many marketers aren’t sure which tactics they should use to provide their company with qualified leads. In fact, many marketers aren’t even sure which marketing tactics should be used as lead generation tactics.

There are seven marketing tactics—I call them the “Magnificent 7″—that are the best tactics for providing companies with large numbers of leads and a significant return on marketing investment (ROMI).

The Online Lead Generation Tactics

First, there are the “online lead generation advertising” tactics:

Search engine marketing (SEM) involves setting up ad campaigns on Google and Bing. When your target customers search for certain search terms (e.g., “golf shoes”), your SEM ad will appear at the top of their search results.

With social media advertising, you use banner ads to target users on Facebook and LinkedIn (e.g., a “honeymoon cruises” ad will appear on the Facebook pages of users whose status is “engaged”). Even Twitter now offers social advertising through “promoted tweets.”

You can use display ads (a.k.a. banner ads) to generate leads on websites. Also, marketers are now getting high response rates with interactive mobile ads for smartphones and tablets.

Email marketing is another effective online lead generation tactic. Many marketers are reluctant to try it, because they’re afraid their marketing emails will be mistaken for spam. But if you use targeted, permission-based mailing lists and follow the 2003 CAN-SPAM Act guidelines, you can help to ensure that your emails will get through to your target customers.

The “Tried-and-True” Tactics

These three “old school” tactics still bring in thousands of leads for companies that use them.

Direct mail is a great tactic for explaining the benefits of a complex product or service in detail. But it’s an expensive tactic, so use it only if you’re selling something (e.g., cars) that gives you a high ROMI, or if your customer has a long-term lifetime value (such as in the insurance space).

Cold calling works best today if you’re selling B2B products. In cold calling, you use a targeted call list of customers (e.g., business executives) who might have a need for your products or services.

Finally, trade shows are still a great way to collect leads because they bring you face to face with customers who may be looking to buy your products or services.

Which Tactics Should You Use?

As many as will work successfully for your type of business, and provide a positive ROMI. Ideally, you should test all seven lead generation tactics, and use the tactics that work best and are the most cost-effective.

Editor’s note: In his book, The New Rules of Lead Generation, David provides greater detail on strategies to help marketers maximize their ROMI through successful lead generation marketing.