I also have an affiliate program where I pay a flat rate commission per lead, however since I need high-quality reviews quickly, I'm leaning towards requesting sponsored posts rather than an affiliate partnership with top review sites in my industry
The amount paid is relative to the audience reach. You should ask questions like - number of hits they get to their publications and if the sponsorship will include sharing your content on their social networks. I have not heard of bloggers doing lead generation campaigns, most of them offer view based campaigns. I would recommend testing before switching your strategy.
This is a tricky one if you're wanting a flat rate sponsored post fee.
I'd lean towards something like this:
Figure out your site conversion rate (even better if you have average referral traffic rates), discount it a bit for a margin of safety, then calculate what each unique visitor is worth.
I.e if you convert 1% of visitors, and your average profit is $100, each visitor is worth $1, on average.
Don't offer $1 per unique visitor though, discount it to a level that you feel confident in (traffic quality may vary).
I love questions like this. As it turns out, much of the time "influencers" overvalue themselves and overall pricing from self publisher to publisher is inconsistent.
There are several ways to handle this actually.
1 - Exposure/Branding
2 - Performance Based
Ideally, you'd always want to pay for performance, however in certain situations the latter may not be available. However doing proper research on both the publication and its audience is key to the offer you propose.
There are a good amount of factors that can add to this as well. However an indepth talk and understanding would be necessary for the most beneficial path for your product to see the most ROI.
Hope that makes sense.