Ted,
Poor joke re:Jack of all trades. Apology extended....
Viglink is not harmful, no need to worry on that account. It's just another method for monetizing the Internet. There's a small fee paid every time someone clicks the link to get through to the final page. I've followed it and others growth and I did not think it was likely you had inserted it.
Instead, either the seller or more likely eBay popped it in when you copied the url as a way of gaining revenue from what I view as the effort of others. (In this case, you.) You copied, you posted, you have the reputation, Birdforum offers the resources and additional reputation. But no one has offered you a small fee for your work. So, unless Birdforum has started to use Viglink, it's a vulture enterprise that profits from the labor of others.
At least, that's my opinion :>)
Best,
Jerry