How many open source projects generate financial rewards to their contributors?

Apart from those funded by donations, I can only think of Bitcoin. Although Bitcoin is open source, the network effect has proven it fruitless to copy the code and make an alternative chain. Early contributors, if they only bothered to stash some coins, have been generously rewarded. Counterparty may follow a similar path. Counterparty benefits just as much from the network effect, hence there should be nothing to gain from forking the code, and XCP is a scarce token that early contributors can get cheaply. However, i used the word “may” for a reason. Most Counterparty users don’t need XCP, or if they do, just in small amounts to pay fees. On the other hand, all Bitcoin users need BTC (all Counterparty users need BTC too actually) .

How about projects running on Counterparty. Can they add a profit motive?

The Lets’s Talk Bitcoin network, although not strictly open source, offers its contents for free. Actually, not for free, you get paid with LTB Coin for listening! Contributors also get rewarded with LTB Coin, and obviously to a larger extent. Advertisement is paid for with LTB Coin, hence the coin has a value. The entire community has a stake in LTB, and this gives some powerful, fair incentives for further growth.

I’m sure there are other noteworthy projects on the Counterparty platform. Which ones? And what are their profit motives?

The profit motive is, as you know, a very strong incentive. Much progress and prosperity are thanks to this. In the world of IT, however, many of the best projects are open source, made by people for people for free. Now, if the best of these two models can be combined, what will this mean for software development?