You will see the horse-shoe blue image when you open a match that has a shared ancestor that ancestry.com has found for you; it won't always be there and you may well have shared ancestors that their search engine can't find for you (i.e. more than 10 generations back, different spelling or dates or location in one of your trees that makes their search engine miss the match for some unknown reason.)
I think we are getting the info on the changes from each other on this board and others listed under DNA. Many of those who are posting have been playing with this DNA product for about 6 or 7 months -- about when ancestry.com started offering it to more members. We have discussed how we have to find all these new tools as they are rolled out...there is no "page" where it tells you what new updates you are getting today (like itunes does when you download a new app for your iphone!!)
That's part of the reason this has been such an active board...whenever someone discovers some new tool, change in the search engine or whatever, they tend to post it and people talk about how they are using it.
Many people don't get very many hints, so you aren't unusual, if your tree doesn't go back enough generations. Generally, the more robust your tree is with generations going back to colonial America, the more matches you are likely to get...just a reflection of the current data base of users. Remember, it rolled out about 9 months ago beyond the most early users...it keeps changing, improving and more members join. A year from now, we probably will have totally new, expanded and neat platform for searching (and maybe that raw data).