Infiltration: Any materials whose main purpose is to produce sales of a product to new and/or existing customers via indirect means.
examples: ads in magazines, web banners, e-blasts, postcards.

Indeed this category is intended to sound aggressive. Infiltration means sending creative pieces driven by your identity out into the world to smoke out from the bushes any potential customers. Magazine ads are a great representation of this. Indirectly your customer comes into contact with your brand. He buys a magazine. That magazine has your ad in it. That consumer flips through said magazine and stumbles upon your ad.

The important thing to remember about infiltration is that it is the most competitive form of marketing you can do. What are you competing for? Attention. On an average day we are bombarded by all kinds of images. It is for this reason that it is so hard to grab people's attention. A good campaign takes not only its competitor's ads in the magazine into account when devising a plan, but also all other visual forms of entertainment that surround us daily.

Another thing to remember is if you pay a lot of money to get an ad in a magazine, newsletter, or website, just because you've paid money for placement doesn't mean anyone is going to see it. It is better to assume that they are not going to see it, and that you should give the ad itself more focus. Advertising is one of the most expensive forms of marketing you'll do based on placement price alone. If you are spending that much money upfront, the message and stopping power of the ad better get people's attention.