How effective is Facebook?

Facebook is better than Twitter in every way. I recommend Facebook.

Why would you even advertise on twitter in the first place? Twitter is the shittiest platform to do that afaik.
Facebook and Instagram are your best options! However it depends on what kind of advertising you wanna do and what you exactly want to achieve. Facebook is better in some cases and vice versa for Instagram.
Im a Operations Manager and one of my strong key skills is advertising, PM me if youre interested in doing this professionally!
Goodluck.

I'm 19 and in collegeand many people my age or atleast people around me don't really use facebook anymore, generally everyone has switched to snapchat or instagram. If you're looking to advertise to an older audience go for it though.

Facebook is for older people. You should consider Twitter and Youtube for younger or more millenial audiences.

Rather than throwing money at ads people will ignore or be angry about why not take that money and put it towards more clever marketing? Giveaways, promotions, clever viral stunts?

Paying for eyeballs the way you are suggesting is only for corporations with very very very deep pockets who don't mind a terrible ROI.

Facebook is really good, if you know what you're doing. LinkedIn is good for B2B, so depends on your target audience

Facebook is the best platform for marketing.. but you need to know what you doing, otherwise youl be throwing money at zuckerbug

I think that it would be more effective to get ads on YouTube instead of Facebook, since you would reach a wider range of ages that way

I like storys and Groups for unpaid Traffic. Facebook Ads aer awesome for my Content Seeding, and its cheap if you target the right audience