For those of you who don't know me and just to put you into perspective, I'm a full-time photographer and 75% of my income comes from microstock earnings. I'm no Yuri Arcus or Lise Gagn, but I make more in microstock earnings than my previous full-time job as a school director.
OK. I've waited a complete month of new best match before commenting on IS's new best match search and how it has impacted my sales. I just wanted to make sure it wasn't a glitch. It's been roughly 6 weeks since the new best match search was implemented and even during the first week my sales dropped dramatically.

As you can see from my graph, my November sales have, on average, been cut in half. For me, this represents sales that I was making back in 2005, 3 years ago. Before the October implementation of the best match my sales were steadily going up and October looked to be close to my September revenues. Then October became my worst month of the year.
What does this all mean for me (and possibly other high-ranking non-exclusives)? Let me give you my thoughts on the future of IS for non-exclusives.
I personally think that my sales will continue to slowly decline (from it's November low) even though I continue to upload regularly because:
1- My acceptance ratio has declined from 80% to 50% because of non logical, subjective image evaluations such as: chromatic aberrations, artifacting, and irrelevant keywords. I don't need to go into details here since all of these have been talked about ad nosium here in the forums. Less acceptance means less images, not to mention that we already have a small upload limit compared to exclusives (which is fine).
2- The new best match search sends my top selling images that used to show up in the top 3 pages into non-existence by placing them on pages 97 or farther still. This means declines in sales from those high earners which means they will also move back in pages from "download" search. In th long term those images will vanish from the eyes of buyers. To go even farther still, non-exclusives will become less known since their images won't be at the top anymore so even rare search by "contributor" will become obsolete. The only search that could help us is "age" for our newer images but that will be short lived because of high volume.
3- New non-exclusive images are pushed back just like top images so they'll never (or rarely) get the sales to take off. I already noticed this happening.
In 2008, IS went from #1 to #2 when I made Emerald at FT (no fault to IS). In November it dropped to #3 behind SS (where sales are stagnant but not declining) and barely beat DT by a few $$. I predict that it'll be #4 in December. It won't take long for it to fall to #5 behind StockXpert since my sales at StockXpert are healthy and keep on increasing. It might take a few years for IS to fall behind BS and 123RF but it will happen if best match stays at it is.
I predict that many non-exclusives who currently make at least $100/month at IS will stop uploading once they can't get a regular monthly income. They will focus on agencies that do. I know that if this happens to me in a few years, I'll stop uploading since it make perfect business sense.
What does that mean for IS? I don't know. There are 1000s of possible scenarios. And my thoughts are purely based on current events.
Just thought I would share my view..... what do you think?
Yanik