PageSpeed says to compress thumb.php images

PageSpeed is an automated system that recommends some improvements that make little or no sense when it comes to WordPress and dynamically generated sizes for images. Best overall thing to do – if the site in questions is socialsparkmedia.com – is find a better host; GoDaddy is well know to be slow. See Recommended WordPress Web Hosting And then work with a cache plugin like WP Super Cache and set up browser caching, too.

Thanks so much. That’s great information.
Do you use a plug-in to resize your images (like smush.it)? Or do you do it manually before you upload? I’m wondering what kind of an impact these types of plugins have on performance.

Depends on how many images you have and how large they were. Your site is very light already; your speed problems are mostly the server itself, i.e. GoDaddy.