Proof perhaps that running an extremely high-quality client-services business also has potential for an exit in the same way a startup does? (Whilst also generating healthy profits in the meantime.)
I don't know why this is downvoted. Apples fall from trees, water is wet, and consulting businesses can be sold for money. Happens all the time. Valuations are calculated very, very differently than for product businesses. There exist consultancies which have sold for amounts in excess of every YC company which has exited through today, although I don't know of any examples off the top of my head which rival Dropbox…
* Consultancies are nominally the experts you call to compensate for gaps in your inside staff.
* You can run a contract with a consultancy first, and consider acquisition only if it goes well and if their people fit well with your people.
If you were aiming for that particular exit strategy, it sounds like it could be much more effective than building a random web / mobile product without a sustainable revenue model beyond "get funding, hope it lasts until someone buys you."