Of course it's around low terms usage of SSD, just don't think about it. SSD drive should bring the speed for your PC and, at any rate, to my mind you shouldn't worry at all about reading/writing/storing amounts. Just keep valuable data in one (better two) several reliable archival storage devices, for example your HDD and some USB or Optical storage and feel fine. I Have a 120Gb SSD cheapest possible smartdrive for over 6.7 months and a copy of main info on removable HDD, some extra valuable files have second copy on blu-rays and usb's. Don't bother yourself thinking about lifespan of your SSD. This unit just brings overall speed bonus to your sys, use it at full scale without any afterthouts and doubts. From my point of view swap file should be also on your SSD (instead of HDD according some advices), because you bought your SSD to boost your PC.
Moreover, if it's new, you have a warranty, and in your interests to find bugs during first using period and if it's used, then you shouldn't worry at all 'cause you can't be sure about really true previous terms of working. Major part of SSDs from my own experience (previously mentioned is the third one, all three works well till today without any special conditions and terms of usage), brakes or have errors during several weeks after the using starts and, according to the internet statistics, if several months past and device works well, then you shouldn't worry next few years, depending on sane)) amounts of writing, of course. Good Luck and long live your SSD.