Oh i wasn't suggesting we overtake the existing HN show function, just that i think an additional one for products making money is a good idea.. much like this product!
Most Show HN products are in the pre-alpha, pre-revenue stage. For them the feedback as well as the eyeballs are of great value. Though there are outliers, the value is usually tilted towards the creator rather than the readers (who are mostly just helping out).
OTOH, products with revenue in Show HN provide at least an equal value to the readers by way of lessons and execution strategies. So I agree that it's a separate class of "Show HN". However, if you put "Show HN: xxx generating $xK/month" it's very likely to bubble up to the top without needing a separate category. In fact, it might be better to not have a separate category since you might get more eyeballs if the links aren't split.
