If you run paid ads, squeeze page is good. With less distractions, you can simply and immediately capture their information in exchange with your offer. You risk loosing those visitors information with a blog, they might not go back to your blog again.
If you use SEO, then it does not really matter, I think. If your site or blog starts to rank high, you can attract thousands of visitor on a daily basis. Then your opt-in form will be very useful. You can even include a link to your squeeze page to increase exposure.
paid ads- squeeze page
SEO, organic promo- opt-in form :icon_rock: