Success can be measured in many ways depending on who you're asking.
I can't quit my dayjob and work full time on my comic to pay my bills, and compared to many of my friends, I have very few followers.
BUT the people who read my comic are so nice and great at commenting, which always makes me a bit tense before I release a new page (will they enjoy it???), but in the end always makes me smile since they seem to like the direction that my comic is going =)
Also, in Sweden, I have been published a few times, which doesn't pay my bills, but it's nice to get out there and to be in the same anthologies as some of my comic idols :3
I've been drawing comics since 1998 (with a few hiatuses inbetween), but been more serious about it since 2014-2015, I think =)