Keep in mind that investors invest for returns. Telling a prospective investor that you want his or her money to grow your business but don't plan on ever generating a liquidation event that pays him or her a dividend is not likely going to work; angel or not.
You may be better served with debt financing where returns are generated in the form of interest payments not equity value growth.
BUT, if equity financing is the plan, you're going to want to develop a strategic exit plan right from the start.
That means identifying prospective buyers, strategic channels etc and characterizing the value drivers for each right up front.
You'll find prospective buyers come in a number of forms; competitors, bigger versions of you, strategic partners, private equity, etc. Each will value your business in different amounts for for different reasons. Understanding this is vitally important for you to navigate to securing the right money, from the right sources, with the most favorable terms.
Once you've qualified and quantified each of them, then determine what (specifically) you're going to need to do to align your business with those prospective buyers generating the highest returns.
This will drive your business model and go to market strategy and define your 'use of funds' decisions. This in turn result in a better, more valuable business whether you exit or not.
Do it this way and you'll have no trouble raising money from multiple sources.
You can learn more about the advantage of starting with a Strategic Exit plan here: http://www.zerolimitsventures.com/cadredc