So you have a limited marketing budget and want to get the most bang for your buck. First off, make sure you have your "aha" factor done. That is your byline which goes on your web site, business cards everything. So instead of being just "Acme Widgets" you add "We catch Road Runners". Assume your audience has ADD. Always.
Next get a couple of good case studies with $. That's right, dollars. Capital recovery period is king. Keep it under one year or find another line of work. Put together a couple 2 page white papers at a high level and make it easy to find and easy to download. For the detailed papers, it's o.k. to ask for some personal information, but not for the summaries. I have left more web sites than I care to say because it just got too complicated. Remember ADD.
If you need inspiration, talk to people in your company outside of engineering and marketing. Ask them their opinion. Just last week I had a great conversation with a recruiter at a hardware management company. She went to a training class about the product (smart idea) and met some folks from Europe who told her they managed 4,000 users with just 4 people. Now that's hot. But you cannot find it on their web site or in their white papers (for which you do have to register).
Forget about building brand image. A lot of the pubs have regional shows in which you can participate and sponser for not much money. Put together a table top display (complete with your artwork and lights for under $10K) and grab a sales person and hit the road. Bring a couple of reprints (you did get published somewhere didn't you?), a couple of white papers and talk and listen to everyone. Pick the right presentations and you will get the leads.
And become an expert in your field and get invited to speak at these shows. Limit your slide shows to less than 20 slides. Do not put your speech in your slide show. Just make 1-3 points per slide, or show a cool diagram, or have a 15-30 second movie showing off your product. And above all, do not spend your time behind the podium. Get off that stage and down into the audience. Talk to them. Take questions on the fly. And shut down the pompous audience members quickly ("here's my card, call me tomorrow and we'll talk").
If you're excited, they're excited and they will remember you. And you will be amazed at the leads you get. Back in my Zenith days the sales guys were complaining they never got any leads. So I got to do the booth that year. I delivered 2,000 leads to the VP of sales two weeks later. It can be done. Do it.