I think was Chris is asking is really more in the title "How do you influence the end user".
Sure, there are a million ways to get basic contact info for end users. If you don't know how to acquire a list of email addresses you're seriously lacking in even the most basic skills. I won't get into that because it's (hopefully) not a topic worth discussing in this context.
Once you have the basic list of "Name, Title, Email, Phone Number" you begin this effort of of trying to get some mindshare. This is sometimes called lead cultivation, lead qualification, etc. The fundamental problem here is that you rarely know what is really going to resonate with this person.
As far as decision-makers for the common security and access-control products, I've seen two main camps. You've got the guys that have been around for a while, and their knowledge of standard topics is pretty deep, but they're not very technical, and the elements of IP (networks, routers, port-forwarding, bandwidth and so on) tend to be a little elusive to them. The other side is the people that are bridging over from the IP world and are pretty good with all aspects of packet routing and switching, but really have no security knowledge between what they've picked up on the Internet and they often think they're smarter than you and/or can figure out the "basics" of cameras and access control and there really isn't much to it.
There are some other sub-genres, but these two groups seem to cover the primary people you deal with on a day-to-day basis (again, IME).
You can already start to see that different messages and topics are going to resonate differently with these two groups. And, from your "Name, rank and serial number" list you rarely know who is who just from a title. The first part of influencing them is getting them to opt-in to some kind of next level discussion. This is the "call to action" froms on websites and similar "give us your email in exchange for this whitepaper" tactic. You're sending out email blasts about new products, case studies, white papers, educational webinars (or more commonly marketing-stuff disguised as education) and you're trying to get a feel for which people are responding to each topic.
Sounds good so far, but there's another wrinkle. People can be in the "It Guy" or "Security Dude" camp, but neither of those folks tend to care about solutions for other industries. And very few of them at all seem to be able to extrapolate from a case study for a school and how that might be relevant at their hospital. So one of the things you'll do if you have the time and resources is try to group them by industry. You can frequently get this data directly if you're buying email lists, or you can figure it out from domain and company names if you've scanned 500 badges at ASIS or something. That figuring it out and categorizing is kind of a manual process and this is usually kicked to the lowest-ranking marketing person in the organization.
You figure out your key value-prop for your product, customize it for each major vertical you want to target, and then start sending out emails trying different angles. At the same time, you're putting some white-papers on your website, writing a ton of blog posts covering all these topics and appealing to different personality types, submitting content to trade magazines, speaking at major or minor trade-show events and so forth.
As much as I hate the "thought leader" tag, that's what you're trying to do. I think we saw a good example of that from th Vicon guy the other day in the Indigo/Arecont thread. Get end-users (or, people in general) to recongize your name, your company, and associate that with knowledge.
Many times the decision-maker at the actual end user is responsible for a lot of different things. A full decision usually incorporates selecting a product for both its IT merits and its Security merits, and few people are savvy on both. As a manufacturer you're trying to convey the feeling of "Nobody ever got fired for choosing IBM" (for those of you old enough to remember/know that one).
You'll usually go through some process of email collection -> Lead conversion (the person expressed interest in being contacted about your product) -> Phone Conversation/Screen sharing demo -> Onsite presentation -> Onsite product evaluation (POC (Proof of Concept)) -> Purchase (hopefully!)
This is a double, or triple, edged sword though. If you're any kind of a real manufacturer in this industry, you're not going to sell direct to that end user that you worked so hard to win over. You need to pull an integrator into the mix at some point. Early enough on so that the integrator is involved in any of the sales pitch and/or system design stuff, but not too early. You have to assess the integrator if the customer has a long-standing relationship with them and make sure that integrator doesn't try to sway them in a another direction due to their own alliances, lack of knowledge on your product, or whatever. The ideal case is the customer has no captive integrator and you're in the position of being able to make a recommendation. If there is an integrator that they already use and want to work with, you need to convince them to support you. Doing that is a whole different topic.
If you're a main-line manufacturer in this industry and your sales people can't hang with a full discussion with the end user, you need to get new sales people. Depending on the size of your org and the scope of your product, you might have "sales" people and "biz dev" people, where the biz dev folks concentrate on particular verticals that have long sales cycles and require a higher-than-normal amount of domain expertise (eg: Energy sector, or even more specifically Nuclear Power).
We're dealing with integrated systems in the common market today, even if 75% of your sales are fairly templated using essentially all your own products (Avigilon, Pelco, Axis (in some cases)). A good manufacturer-level sales person understands their product, competitive offerings, and all the components neccessary to make their product part of a comprehensive solution. If you're a pure camera company, you need to know a fair bit about all the mainstream VMS's. If you're an end-to-end company, you need to know a fair bit about all the other components because there are going to be many cases where for whatever reason the end user doesn't want your end-to-end. They might have a legacy investment in something else, or they're going to migrate there later, or who knows what. But, I think the end-to-end sales people need to be MORE knowledgeable overall about the general market than a similar role at a single-product company (Camera, VMS, etc.)
Just like the sales person wants to deal with the "decision maker", the end user many times wants to deal with "the person who can answer my questions". Sales people need to be more technical, if you're calling your SE 10 times a day and/or about every lead, you're not qualified to sell your product. SE's are valuable resoources and are best utilized for getting into the details, doing POC's, etc. They're not there to answer any question that contains an acronym.
If you're at a total loss where to start, I'd suggest a bunch of basic SEO topics. (If you got this far, sorry of the wall of text, thanks for reading ;) ) So much of this revolves around the web today that website optimization, lead collection/conversion/tracking and so forth are critical to high success.