I have let it my domain name expired after it got hit by PANDA on 24th june.
My domain expired on 7th july. Now would you suggest me to renew the domain name or let it expired.
If you mean should you let the domain expire and switch the site to another domain, then it may be OK for a while but then the new domain will probably get pandalised too unless you cut out the bad bits.
Oh, and a .com renewal should cost about $12. If the site makes less than that a year then don't give up your day job <G>
I would keep it regardless. If you spent even just 1 year building a brand and a website, why give it away to someone else?
Even under the worse conditions of a fully deindexed site (Which would suggest shady practices) Change ownership info in your registrar and 301 it to an affiliate offer somewhere with your ID embedded.
Just my .02 cents.
I still keep a +5 year old heavily penalized domain, just because I don't want someone else having all the backlinks still out there!