[I am not getting much clicks on my Fiverr gigs, is it ok to change my gig thumbnail?]

yes, you can update your gig thumbnail to attract clients.

[Decrease impressions and clicks day by day.]

Some Main important tips to make your gigs top-ranked using Fiverr SEO are:

• Your gig must have an attractive title.
• Your gig must have good tags and descriptions.
• Your gig should have basic and popular keywords in the title, tags, and description.
• Your gig title, SEO title, tags, description, and the URL of the gig should have the same keywords.
   

[How have your impressions been this week?]

Some Main important tips to make your gigs top-ranked using Fiverr SEO are:

• Your gig must have an attractive title.
• Your gig must have good tags and descriptions.
• Your gig should have basic and popular keywords in the title, tags, and description.
• Your gig title, SEO title, tags, description, and the URL of the gig should have the same keywords.