Indeed you are flat out wrong for pretty obvious reasons. Investing in Apple (Nestle or whatever for that matter) means that you are buying their stock (shares). And if your share (no pun) is good enough, you can literally overtake the company and make decisions about its future.
I should never have used the word "invest" when designing Just-Dice. By putting your coins in the site's bankroll, you aren't "investing" at all. You are only helping to fund the site's bankroll.
You are certainly not buying "shares" in the site. Even if you provide 99% of the bankroll, you still have no say in how the site is run, and you certainly don't own any of the site.
It's probably too late now to change the terminology used, but to be clear when I say I "invested" in the site, I mean I added 60 BTC to the bankroll which the site is slowly losing for me. I don't own any part of the site.