I think the SEC would see a difference. By investing you are only bankrolling. If investment was offered as shares then maybe. There are no real regulations for this sort of stuff at the moment.
Agreed.
In retrospect, "invest" was a bad word for to pick for what people do at crowd-bankrolled dice sites. It suggests to the uninformed that you're buying a share in the site when of course you aren't. I don't know what a better pair of verbs than invest/divest would be though. "bankroll/unbankroll" is clumsy, and has the disadvantage that "bankroll" is a noun as well as a verb, and so is confusing. I guess crowd-funded bankrolls are new enough that we don't yet have a good vocabulary for describing them and so "borrow" words from a related but different activity.
The SEC seems mainly concerned with unregistered share offerings, such as in the SatoshiDice case (Edit: this quote is
from the SEC):
An SEC investigation found that Erik T. Voorhees published prospectuses on the Internet and actively solicited investors to buy shares in SatoshiDICE and FeedZeBirds. But he failed to register the offerings with the SEC as required under the federal securities laws.
What sites like dice.ninja were offering wasn't anything like a share offering (it's more like a long-standing bet against the regular dice players) and so I doubt the SEC would be interested.
My first response was too quick, and I didn't see this response until I continued reading, so I'll go into more detail.
It seems what is throwing people off is the term "share offering." Shares are just one type of security, and the SEC's purview is
all securities. For example, corporations have "shares." Limited liability companies have "interests." It's just how the businesses are structured, but both shares and interests entitle stakeholders to a portion of profits. Both are securities, and both are under the jurisdiction of the SEC because it regulates all securities.
Also, there are ways to structure businesses so that what you own is not a portion of the business itself (that is your shares/interests don't entitle you to vote on business decisions) but only entitle you to a share of the profits or losses of the business. This is certainly how the dice sites are structured. You don't own any part of the site, just the profit/loss. But that ownership you bought into is still a security.
The way JD, DD, DN, DB, ED and every other site that takes investments and allocates a share of profits based on that investment is structured is as a security. You can call the "unit" whatever you want: shares, interests, percentage... that doesn't matter. The SEC calls it a security.
If you're interested, here is the exact definition of "security" from the 1933 Securities Act, Section 2(a)(1):
The term “security” means any note, stock, treasury stock, security future, security-based swap, bond, debenture, evidence of indebtedness, certificate of interest or participation in any profit-sharing agreement, collateral-trust certificate, preorganization certificate or subscription, transferable share, investment contract, voting-trust certificate, certificate of deposit for a security, fractional undivided interest in oil, gas, or other mineral rights, any put, call, straddle, option, or privilege on any security, certificate of deposit, or group or index of securities (including any interest therein or based on the value thereof), or any put, call, straddle, option, or privilege entered into on a national securities exchange relating to foreign currency, or, in general, any interest or instrument commonly known as a “security”, or any certificate of interest or participation in, temporary or interim certificate for, receipt for, guarantee of, or warrant or right to subscribe to or purchase, any of the foregoing.
"Participation in any profit-sharing agreement." You can call it whatever you want, but it's definitely this. That means it's definitely an unregistered security.
tia
Lets let the courts decide!!! 
