WordPress as Blog Aggregator

Hard to appreciate the concept since I can’t read the text (though it looks pretty!), but just wanted to let you know that I got a weird popup when I clicked in the category select dropdown. I didn’t wait around to see exactly what it was, but the title bar of it said something about a “new offer”.

You get the popup because currently I am using a free service, soon I am going to purchase a hosting account so it will be gone.
Thanks