Fortune 500 company reached out to post a content on our blog.

Forget asking for advertising. Simply ask how do they promote their guest posts and send your policy of guest posts that includes them sending a link to he article in their newsletter and posting on Twitter and Facebook and you also promote their article on your channels. If you want to know more how to strategise this partnership to squeeze all the juice or even get some sales, contact me on https://www.upwork.com/fl/auksez.

Thanks guys for suggestion. We agreed on a deal and its win-win for both parties.

I would say "yes, that sounds great and I would love to help" and then claim dumbness and ask "so how does this usually work? Because I no nothing much about SEO and cross posts etc. I can't even spell 'know.' How do you provide reciprocal value? Do you pay or back link ...you know what?"

Better to ask than guess. It will set you up better for next time too. And remember that though its a fortune 500, its really just some staffer just doing their job, probably without the company credit card, that you are talking to

I’d say ask for payment (sponsored post) and make sure you make it clear to your end users it’s basically advertising hiding as content

Backlinks and cross promotion.

I'd try to work out some kind of promotional deal. They post their content on the blog and then they advertise the blog through their channels somehow.