After acquiring around 100 cats and accruing over 1 million dollars in cat worth, I can not begin to describe the relief I, and more importantly my ears, felt after pressing the sell all button.
I like the idea where as a player you can decide to go for more valuable cats (upgrades for tier frequency and combining) or for quantity (focusing on clicking the cat food). An auto-clicker, of course, annihilates the debt.
Special mention to the cat names. I particularly like "Fishlips" and "Bingus." There are some really good cat names in there.