Incredibly viable. If you make something people want, companies will want to buy that. The plus side is you could make the bulk of the return due to lack of dilution. The downside is the valuation could be lower (though I might be totally wrong about that) due to lack of formal valuation in the financing market, and lack of social pressure to make investors happy.

I'm very curious to hear others' insights on the valuation issues with bootstrapped companies. I share your concerns here.

>>Is bootstrapping really a viable path to an exit in 2015?

Academic startups where the technology is based on research are bootstrapped until the commercial viability of their ideas is demonstrated, wherein they sell their patent portfolios. Is this an exit?

We are running such a company. We were founded in 2011, have a quarter million users, revenue, etc.

In many ways it's easier today because of so much open-source software, and so much to disrupt :)

I think the opportunities are there just the same - it just takes a while for these companies to grow to the point where they are well-known.