I strongly believe that most web sites are leaving a lot of money on the table by not having their ads in-house. It will be more work (and cost) in the short run, but a good ad salesman can find those customers who really want to target the people reading your website in ways algorithms do not. The big automakers and fast food don't care about targeting - nearly everyone is a potential customer so they can get everyone. Most care about targeting and so by selling direct you ensure that their ads never go to someone who won't buy anyway because of the algorithm.
3 steps:
1 - fund high quality, totally free content, great UI, minimal ads
2 - poach customers from subscriber sites, wait them out. will take about a year. they'll go broke.
3 - start to optimize for "engagement" (ad views). profit.