The advertising on the back is subtle enough I don't mind it at all for personal cards. There's a level of professionality at which you wouldn't want it, but at that level you'd also want a less stock image and layout than they offer for the free cards.

I've never had a spam problem from them.

The print and cardstock quality are far above what you get with a laser printer (I have some of those too), though there's the advertising and limited layout issue.

"Free" is really a few dollars for shipping. It might have been as much as $5, which would be, what, 2c/card? Cheaper than the Avery sheets alone, last time I priced them.