TIP$TER is free, and is likely to stay free for the foreseeable future, because:
1. It was inspired by freely available information, especially William Bernstein's excellent series of articles at http://www.efficientfrontier.com and Robert Arnott's "What Equity Risk Premium Is Normal?", knowledge of both of which the best independent financial forum on the Internet – Bogleheads – kindly and freely disseminated.
2. It helps people. TIP$TER has already changed some lives and enriched them. That's a good thing.
3. I (TIP$TER's creator) am an experienced – and very capable – intellectual property attorney. If you doubt it, check out my profile. I developed TIP$TER to serve, in part, as a vehicle for getting my name out and advertising my intellectual property services. (While I'm at it, let me add that I – with my low overhead – am rather affordable. Ask me about my rates).
4. TIP$TER is new and few people know about it; and people won't risk money on a product that isn't known.
5. There are a lot of other free online financial planners and simulators. Although TIP$TER is superior, TIP$TER can only compete by being free.
6. Without a sufficiently large user base, the trouble of charging small amounts on a small sales volume would not be worth the trouble, nor could such small amounts sustain the maintenance and support needs that paying customers expect.
TIP$TER is operational for only a limited time because:
1. It gives Prospercuity control over its software.
2. It sunsets old versions, which may have bugs, and promotes the dissemination of new versions in which the bugs have been removed.
3. It protects Prospercuity from software piracy. If the software is pirated, it will only be operational for a limited time.
4. It enables Prospercuity or its successor (if any) to monetize the software if the opportunity presents itself.