My preference would be for Steemit Inc. or any interested party who could work well with the various front ends, to not sell ads directly, but instead run an advertising marketplace system and receive a small percentage cut or commission of the funds going through it.

This would be similar to the now defunct Project Wonderful, an ad system which I loved... or in some ways comparable to the current and crypto friendly Anonymous Ads.

This would keep with the community driven spirit as it would be the content creators themselves directly selling advertising space and not the hosting site. Outside advertisers could easily leverage the system, running campaigns with settings allowing them to advertise across posts meeting their criteria, such as particular post tags, author reputation, etc. Users in turn could avoid bid bots for promotion by instead buying ad space in the footer of another favorite author or well known Steemian in their particular area of interest.

Common settings in these services allow users to manage their own ad blocks to reject ads that may not fit their blog as well.

This inherently leaves the choice of ad participation up to individual content creators, and consumers who are against ads can likewise avoid anyone who "overdoes" it or hosts ads not to their liking.

Here's a post I wrote months ago specifically discussing Anonymous Ads. This service does not work within the post bodies on front ends like Steemit and SteemPeak, which I assume is simply a security setting of some sort. Rather than reinvent the wheel, it could still be possible to simply whitelist this code and encourage a partnership between Steem and Anonymous Ads. A-ads starts dealing in Steem in addition to Bitcoin, massively grow their content network and inventory of advertising slots almost overnight, and Steemians get community controlled advertising that creates a secondary income stream with no payout time limit basically enabling evergreen content earnings. Steemit Inc. could either negotiate a split of the commission in exchange for whitelisting and integrating A-ads as the official advertising network of Steem, or set themselves up as a major referrer and earn referral revenue. Likewise, if outside advertisers do begin purchasing with Steem, the potential price appreciation alone can help with Steemit Inc's financials.