i am constantly monitoring various kws and apart from other ranking factors ive noticed that tf-idf could be the key factor right next to exact match. i have a lot of partial match backlink that eventually brought me to page two on easy-mid comp kws, then i made a handful exact match backlinks that positioned me nicely (top 5) but i lost them and i went back to second page immedietely. i never really did any exact matches in backlinking to avoid penalties that people often cried about. however exact match is not everything. backlinks need to be done very stricte.. if you want to rank for "black motorbikes", and you put anchor "free red motorbikes in london" in article about cars then thats still not enough. motorbikes are not cars and therevore tf-idf even of that simple page with link is really low very closely to zero and irrelevant spam... of course then there comes tf-idf of whole domain... then we rinse and repeat> now we got hundreds of irrelevant backlinks we thought are relevant. maybe for human cars are very close to motorbikes but for search engine not. they could eventually rank you there if there was no competition with bigger relevancy thats why i believe our exact match should be included on every page on money site. even if its multiniche site. and then there are tons of related keywords that also need to be included on money site. but not just where we have our ranking article. we need to include them (in case of multiniche site) in every, related, page (example supporting pages). and in case on single niche sites - literally everywhere by doing this we maximise the tf-idf of page and domain. then we once again need to make sure our main keywords appears more often than related keywords on every page we did put them. now on-page is done. we need to follow the exactly same process while doing tier 1. links: - without text (with exceptions) - below 400 words (with exceptions) - without exact match/related kw as anchor - without tons of related keywords included in article and without one in h1 and/or title tag obviously are generally unrelated. its like scraping a random article from the net and hoping it will become "contextual" if we put our main kw there 3 times. if we have a lot of backlinks made without maximised relevancy, the majority of them will be seen as irrelevant stuff (or stuff just barely relevant) so >> our general backlink profile is spammy/not related. only exception to tf-idf is to get stronger links. they will help us even if they are not as much contextual as they could be. but thats a waste anyway. so tf-idf is one thing that will help us alot. yet theres one more thing that might help: maybe each of our T1 backlinks should be targeted. We wont just pick random kw from the bag of relevant ones to put on title tag, then another random one on h1, on url structure, and a lot of random ones in content. It would be better than nothing but maybe they need to be perfectly targeted. maybe it should be one and the same keyword for title,h1,url, with increased density, etc for single backlink. I believe it would be much better than mixed backlinks (still relevant with high tf-idf, which are good already). So its like we step 2 steps further instead of one or zero. What you think?