I recall what Cameron Brown wrote about getting sponsors a few years back. It sounded like his father went out and got some of the sponsors and he got more than a few and they weren't all directly related to triathlon.
Also your family or partner could be your number one sponsor if you are lucky.
To get really good all by yourself would be very hard. Maybe if you study sports science or something related you could get alot of the info. But otherwise you need to be around people with that knowledge.
The above is pretty obvious.
The team concept is where non-drafting triathlon is headed. I agree it is hard to be out there promoting yourself while training at the same time. But if you are full time training then you should have time and it will be better to get sponsor money than be tied to a bad job. The team thing done right can get more exposure than an individual. Although to me Macca's personal media team are getting more exposure than Team TBB or the Commerzbank team.
The bank HSBC is trying to go more global so a team could try them.
'Networking', or talking and listening to people in bussiness will help also like you say.
Rappster has thought outside the box and is doing alot of things right in promoting himself. he has good technical knowledge and is using that in part. There are still more opportunities like that to align oneself with triathlon online. use your strengths.
The other thing is 'how do you stand out in the crowd'. The crowd being all the other athletes who get a couple of top 10 placings in races each year and who are seeking sponsors. Somehow you have to be noticeable and have a presence. Petr Vabrousec stands out to me for all the events he places top 10 in. But how do others get noticed? The media following triathlon doesn't compare with that following soccer, but you would need to get to know them. Either that or create your own image via your own various media.
New products or new companies often need exposure. It is a bit tough for the athlete to work out how they can help someone elses company(but you could do it). If you really had great ideas you could probably create your own product/company and make that work.
If I have time or think of anything else I will say on here. or maybe in my blog someday.
G.
www.TriathlonShots.com
http://www.TriathlonShots.com Full event coverage of triathlon/ironman in photos.