Q: Before using JoomlaStats I was using another tool to count number of visits. Until now I had 63.256 visits. Joomla starts out-of-the-box with 0 visits. Can I keep my number of visits and let JoomlaStats display 63.257 for the next visit to my site?
A: When using the latest mod_jstats_counters module, you can adjust the total visits with any + or - value...
You can do this in Joomla backend. Go to modules - site modules and then find the counters module. There you can find value 'Offset'.
Enter the previous number of visits here.
Q: I used JoomlaStats for a while now and I want to start the number of visitis from 0 again, or decrease it by 534, without deleting any data.
A: See previous answer, however use negative number (-534). If you want to let the first visit as 1 then look at the number of visits you have right now (i.e. 85.254) and enter this as a negative value (i.e. -85254)