You would be surprised that most charities spend excessive amounts of their donations to raise more money. An online charity that is using its money to employ people is a better charity than one that publishes glossy brochures or takes out advertisements.
Do you have any figures to back that up? Most charities here in the UK publish their expense ratios (i.e. how much is spent on admin, fundraising, on the actual good cause etc.) and they tend to be fairly efficient.
A lot of big charities in the UK employee "clipboard-nazis" near busy shopping areas to get people to sign up and make you feel guilty if you don't. These people normally earn 25 GBP per sign-up (which takes on average 10 months to recover iirc). Other charities spam you with mailings.
Now clearly this works: they are raising more money this way, but the side effect is that people like me refuse to give to a charity that hassles me every time I go to the supermarket, and spams me every time I give them money.
These days, that is generally done through an intermediary firm. I don't think many charities hire their own clipboard-wielding youths, so they wouldn't be counted as employees.
By the way, I had some trouble figuring out the right term to put into a search engine. Turns out the industry term for this is "face-to-face street fundraising". And in the UK it's sometimes called "charity mugging" or even "chugging", which you have to admit is more amusing than going straight to Godwin...
Some charities do employ their own staff, because they want greater control over the process and staff who know about the charity, rather than agency staff who might be 'selling' a different charity each week.
Even if they're an agency, the ones I know of are paid hourly, not per sign-up.
My takeaway is that there are plenty of large charities that spend more than 90% of their revenues on their mission and plenty that don't. For me, the big ones that do 90% makes it hard to feel great about a smaller charity that only hits 70% (but then I am a crank that dislikes solicitation).
It is preserving the sum of knowledge being generated on the internet, which is orders of magnitude faster than any other information and data generation system ever in history. It is extremely important to keep records of everything we do online. Saving a life now is great and all, but documenting history like the archive does is essential for history to be preserved.
Also, to generate revenue they would have to privatize some of their data or start selling ads, which for the same reasons wikipedia is funded by donations, doesn't work with public services.
Same with wikipedia. It's ironic that the current "Please donate to wikipedia" banners actually annoy me FAR more than little relevant adverts would.
Maybe scanning books in or archiving live concerts or saving some geocities pages is something you're interested in, but I'm skeptical it's really preserving history for the good of mankind.