I need to add blocks to the main content of a site.
Those blocks contain multiple (between 15-30) links to different websites (with related content).
I currently do have good SEO and before I develop the structure I would like to know what practice is better:
- Create an iframe containing the linked sites.
- Add the nofollow attribute.
- Add a JS onclick listener that changes the window.location.
What option is better for SEO and why? Can you think of a fourth and even better option? Thank you.