The web is awash with articles written and published that have no ads, but consist of content which has been written to promote products/services where these pr

The web is awash with articles written and published that have no ads, but consist of content which has been written to promote products/services where these products/services have paid for that content to appear and rank well organically. What I presume you call ads can be viewed a transparent boosting of ranking transparently using money. So binary classifcation of ads/no ads is going to tricky.