Have you ever had the email: “We have produced this article/infographic/other document which we think would be a good addition to your page about (blue widgets)”? You probably have. Many people don’t know if it’s a good opportunity or something to be ignored. The answer is probably in-between.
Firstly, why are they offering you this content? The answer is, of course, to generate a link to their site. But if including the item improves your site, that’s a win-win, surely? Indeed it is. If your page is light on content, it’s an easy way to add something useful.
In terms of SEO, it’s fairly irrelevant. I’ve seen it claimed that there’s a tiny benefit from linking out, if the site is an established reference; but it won’t be anything worthwhile. Conversely, it’s not harmful, as some people fear. But the link might take people away from your site, and that should be a consideration.
My suggestion is that if you genuinely think what’s being offered would enhance your website, why not get your own version made? If it’s an article or an infographic, the cost and effort should be minimal, and the relevance a lot higher. If you can’t be bothered to do that, why are you thinking of running somebody else’s version? Just because it’s ‘free’?
It’s highly likely that the offer was part of an SEO project, and if it came from somebody you’ve never heard of, you’ll probably be part of a big circulation list. So if nothing else, I’d recommend that if you’re never going to be interested, do not reply, or you’ll get a lot more of these offers in the future.