Advice from experts

I have three tubesite. Now one of my website has daily 1600 visitors and others have very low.
sexxtp10.com
anywheresex.com
everywheresex.com
I want to increase organic search but facing hard time to do it. Now what I do is:

1. Backlink with other website using linkspun
2. Publish video in twitter,reddit and 2 forums
3. Sometimes I do comment in different website
please help me to make a direction that will increase my google index and organic search. Thanks.

Buying links on adult forms and exchanging links, both are good options. No other way, If you are thinking about outreach and all that stuff. It wont work in adult. Offer money to other tube sites, they generally sell for year basis.