Animoto, a site that lets users edit musical slideshows, has taken an unspecified investment from Amazon.com (NSDQ: AMZN). The NYC-based company lets users upload their photos and choose a song — the system then assembles it into a slideshow or music video. The service launched in August of last year and claims 150,000 users. Not surprisingly, it touts a Facebook app with 750,000 users. The slideshow space alone is very competitive. In addition to Slide, there are plenty of smaller ones. As for Amazon’s participation: don’t necessarily assume this will lead to a strategic relationship. (Indie music retailer Amie Street, also invested in by Amazon, doesn’t have one.) Animoto is a customer of Amazon’s web services, which is supposedly how the two sides came together. Release.