Great images are often what separate a great website or blog from a mediocre one. A few well placed high quality stock photos greatly improve the look of your site.

Studies show that websites and blogs with images have a higher retention rate and return rate than those without. That means that your readers stay on your site longer than normal, and have a better chance to come back for more later. Without question if you want to build a loyal readership, you need high quality stock photos.

Finding a great deal on a stock photo is much harder than finding a stock photography website. iStockphoto and Dreamstime recently raised their rates significantly, and Shutterstock forces buyers to buy a "Subscription" to their service. And so we present to you the 5 best stock photography websites we have found. Some of these you may have never heard of. But once you see the benefits, you will want to use them often!

1. Warmpicture Stock Photos

Warmpicture Stock Photos is the only website we know of which allows you to buy direct from the artists. These are the same great photographers contributing to all of the major stock agencies. Because you can purchase direct from the artists, you save a lot of money over iStockphoto and Fotolia. You also directly support the photographers, which is pretty darn cool!

Whereas most stock agencies boast of huge libraries, Warmpicture has a concise library of premium quality. That means you will find nothing but high quality images. This is a welcome change for most of us and really makes finding the right photo a lot faster. Warmpicture uses Paypal for its payments, which is important because it ensures very secure transactions. And you don't even need a Paypal account to use it.

2. Graphic Leftovers

Graphic Leftovers is a relatively new entry into the world of stock photos. Like Warmpicture, their image library is smaller than the major agencies. But also like Warmpicture, they have a higher quality library than most agencies.

The price is definitely right at Graphic Leftovers unless you are a blogger. They have a simple scheme - one size and one price. Image prices can be set by each artist, but most set them at $6. Being able to purchase a full resolution photo for only $6 is pretty amazing. The drawback is if you are a blogger and only need very small image sizes, $6 is a lot more than you need to spend per image. For anyone needing larger image sizes, Graphic Leftovers cannot be beat.

3. 123RF

123RF has been around for several years, and is a sister agency to the much larger Inmagine macrostock agency. They offer pay per download images, as well as subscription plans for buyers who need a lot of images.

There are a lot of things to like about 123RF. They have a very slick looking site (which is clearly patterned after Inmagine). Their prices are much lower than the major agencies. And they share 50% of their commission with the artist. By comparison iStockphoto pays many of its artists only 15%!

123RF has over 9 million images, which means you can find pretty much anything you are looking for. But just like other huge stock photo libraries, that means there will be a lot of low quality photos clogging up the search from time to time.

4. Bigstockphoto

Bigstockphoto has been around for several years too. They were recently purchased by Shutterstock Images, but continue to operate as an independent website with their own pricing plans.

Like 123RF, Bigstockphoto has both the advantages and disadvantages of a huge library with several million images. They recently made changes to their search engine which improved results. Their credit packages are very affordable for both bloggers and website owners who need larger images. I also appreciate that their website runs very smoothly compared to the larger agencies with far fewer hiccups.

5. Dreamstime

Dreamstime is the largest agency on this list, and has long been one of the best. They offer a large library, a slick looking and smooth running website, and several different plans for credit packages and subscriptions.

Dreamstime has a huge, varied library. Their collection is a little more "artsy" than the usual stock.

Dreamstime has a vibrant user community, including regular blogging and a quality message board.Their prices are lower than those at iStockphoto and Fotolia, though the gap has closed with recent changes to their price level system.

One final note.

Beware of Free Photos

Many bloggers and webmasters make the mistake of turning to free photos (or photos they mistakenly think are free) to save money. This is often a huge mistake. The old adage "You get what you Pay for" holds true in stock photography. A poor image is likely to turn your readership away.

Another danger comes from using photos found on the internet without written permission from the photographer. Even if a copyright symbol is not displayed, the photo is still the copyright property of the photographer. Using these photos without permission can get you into hot water.

Stick to purchased stock photos so you are sure you always have a license to use the image legally.