A question for demos...
 

Came across this ad on a local website that allows free buy/sell.

Order your Stampin' Up! products at consultant discount price

Order is going in soon!! Get your supplies for Christmas cards, or get some Christmas shopping done! You get my discount of 20% off, so everyone can save on great products! (tax and shipping on regular retail). Contact me for more details if you are interested. No parties, no obligations, just order what you want and save! Catalogue and current flier can be viewed online!

As a former demo, this irks me as I know how difficult it is to keep the business going. Is this allowed?

Yes, demos can run their business as they please, and that includes providing whatever discount they want.

Oh, I know that. It's the advertising I was wondering about.

I just ordered from a banner ad here that advertised an SU special. I was happy to get the 20% discount as shipping is the same, no matter who I buy from.

Yes, such advertising is allowed if the demo has approval from SU. I know of other ads like that that have been aproved.