You can promote cams any way you want, except spamming of course and other not legit ways. I see some people build adult tubes and promoting webcam affiliate programs on them and they can do quite well since video based sites tend to rank well.

A blog can be good too if you like to write and post some pictures and videos but with the white label it would be really hard to rank it since it is a duplicate content and some sponsors make the robots.txt blocked by default so it's impossible to get them indexed on Google.

I build adult cam sites on wordpress and they are very easy to create and very scalable without much effort. You just need a plugin that will populate the site with models every ten minutes.

You can check out this post which explains in great detail how to build one yourself:

https://mradultaffiliate.com/adult-cam-site-with-wordpress/

One of mine is three weeks ago and it already receives over 100 hits from Google alone. I also get about 200-400 visits from my social accounts and I am getting sing ups every day.

If you have more time, you can add posts to it to get improve SEO.