I appreciate greatly the sentiment but I'm not sure I understand what you are doing. In the middle of someone else's listing description, you put a link to my site? Isn't that somewhat unfair to the person who submitted and going to dilute their brand a bit?
Granted, it gives the opportunity to make the listing a bit more article-like, but I'm really on the fence about this one. Part of me thinks it's an amazing idea (OK, so I'm a bit biased cause you linked to me

) but the other part of me is not entirely keen on it.
Perhaps if it was done a little differently...Not sure what you could do with all of the amazing beads they sell and need some inspiration? Check out another of our arts and crafts-related sites that has this list of free beading tips to get your creative juices flowing.
I wouldn't put it in the second sentence of the description but closer to the end. Where you have it now doesn't really flow naturally. Depending on how you did it, you could make it more like a related posts functionality. That way it would be more like what people are used to seeing and not sort of short-circuit the description like it does now.
The beading site does have a Tips & Tricks blog-like section. Granted there are no how tos and they all look like PR pieces rather than a tips section. Normally for a site like theirs I might suggest linking to their own article section but there's not much depth there. They remind me of article directory pieces. (They don't appear to be but they sure read like it.)
Are you thinking of doing this on the free listings only or all of them where it works?