I took a course on biz plan development in college from a pretty damn successful entrepreneur in tech related fields (who does angel investing himself). He says most investors will initially skim over most of your plan, and look for the following things:
1. Hard stats showing proof of demand.
2. Description of market / trend line of market.
3. Graphs and charts. They apparently love graphs and charts, so try to express as many relevant stats as possible through them.
4. Pro formas. Make sure to include the projected gross profit margin (percentage of revenue that is profit, e.g. 35%). For an internet marking biz model it could probably be very high, like 90%, since expenses are often so low compared to revenue.
5. Capital requested.
So make sure you make a compelling case with 1 through 4 :rasta:. Of course if they're still interested they'll look at the rest of the plan too, so don't slouch off on that either.
In fact, if you want, I can send you the plan I submitted for that class (got an A). It's not a real business, but it exemplifies this guy's approach to business plan writing which you won't find in the generic how-to guides.