I think for almost every blogger, whether you have 1000 followers or 100,000 followers, at some point you will have some interactions with brands and PR agencies. From my experience I've put together a sort of 'perfect world' scenario of how to manage this sort of relationship effectively.
PR: Make it clear what you expect
As a blogger, I'm not naive enough to think that every single PR has the time to trawl through my blog to assess the suitability of their product. Some releases need to hit as many influencers as possible, whereas others are a little more tailored. However, more than once I've produced a post I thought was high-quality and incorporated a product into my blog in an authentic way only to have my contact be disappointed it wasn't a single product review. If there are any special requirements you would like for a feature (like a link to a specific website for the product or a certain week content should be posted during to work with a larger campaign) then it's best to say things up front so you get what you expected. It's also pretty poor to send a product out *then* try to impose specific conditions on someone. If we're told at the outset then if we can't make something happen, we can tell you right away that it isn't going to be the opportunity for us.
Blogger: Manage expectations
If you're contacted about a product you agree to review, the least you can do is let your contact know if it'll be a bad review beforehand or if you don't think it makes the cut for your blog. I also state on my Enquiries page that there will probably be around 30 days between receiving a product and reviewing it (a bit longer for skin and hair care, for obvious reasons) just to try and avoid any miscommunication or unnecessary chasing.
PR: Don't chase someone after 3 days
I'm pretty meticulous about keeping track of when a product has been received, noting the post it will be in and ensuring all links are sent out to my press contacts as soon as is practicable once a post is live. However sometimes you will get chased every few days about where your post is when the product only just arrived! I *totally* understand that people are just doing their job but at the same time, a blogger is often testing out a few products at a time so we need to give yours a fair trial too (not just use it once - though I'm sure some do!) To try and minimise receiving constant chasers (which can honestly be a bit stressful) I just give the date the post is planned for and let them know that I'll send the link over once it's live.
Blogger: Keep your contact up to date
Ok, so you agreed to consider an entire collection for review - you might want to tell your contact that the £200 worth of products has arrived safely! No matter how big or small the product is, if I was approached to review it, I note it in my planner to be crossed out once I've confirmed I have it and everything is ok. Likewise, if you've had to bump back a review then let your contact know. You might be fully-aware that you haven't forgotten but you need to tell them that too if you indicated a date!
PR: Make things clear
70% of the email enquiries your typical blogger gets are spam or border on it, so if things aren't clear in the subject line, emails can accidentally get filtered out when we get a bit 'delete'-happy. On the Enquiries page of my blog I state the kinds of emails I will not reply to ('SEO Expertise!', 'Tailored Articles for Your Blog!' - you know the ones...) However generally I assume that if an email isn't addressed to me specifically, a reply isn't expected unless I'm interested in the opportunity. I'm not an idiot: I know it's largely a copy and paste job but if an email says 'hi Jasmine' then I will definitely reply either way! If a mass generic press release email is sent out, I tend to assume a reply is only expected if it's a 'yes, sounds great!'
Blogger: Make time to reply
If I have such a thing as a 'blogging resolution' for the new year it's to maintain control over my inbox! I'm actually pretty on top of things now and reply to everything in my 'Need to Reply' folder every two days. It's actually more overwhelming not to because otherwise it seems a massive task that should be left for the weekend, which isn't good relationship management. I try to put on an Out of Office if I'm just too busy with work or whatever to deal with my inbox for a few days, which also avoids being chased for a reply (which just means another number in the inbox!)
PR: Don't leave us hanging
*Press Release into inbox - 'please contact us for samples'* Blogger: wow, this new product looks amazing! *replies immediately and enthusiastically. Waits... waits.... waits* - you get the picture! I'd honestly rather be removed from a mailing list if you have no intention of ever working together; it just seems a waste of time and energy otherwise. I always consider how I might feature a product before replying to a release so it's frustrating to have the effort of coming up with ideas totally ignored.
Blogger: Don't bite off more than you can chew
If you have no ideas for how you'd feature a product or you're going on holiday for a fortnight and won't even be able to collect it from the delivery office until you're back; just say so! Obviously some brands send things out without consulting you but they usually aren't expecting anything immediately from you. However don't actively accept a product that you have no intention of featuring. Never. Ever.
PR: Be honest
If you don't have enough samples for everyone then just say 'apologies, we can't send you this release this time round but we do still value our relationship with you' or don't send the email to EVERYONE indiscriminately, knowing you'll end up ignoring half of the replies. Also, if you have certain expectations when you send out a product: we'd rather know so there aren't crossed wires later down the line.
Blogger: Be honest
If a press release is framed in a certain way and you don't think you'll be able to replicate what you think they're after; be frank about it. If you receive an email with the subject line 'Perfect Christmas Gift' on the 15th of December and you've already done your Gift Guide or couldn't get a high-quality post out in time - just say so! 'This looks amazing! I won't be able to feature this as part of my Christmas content but would be more than happy to review it for a later date if that works for you?' - should do the trick. If they say 'no' then accept that they had a certain campaign in mind for a product.
What are your golden rules for managing blogger/press relationships (whether you're a PR, a blogger or both)?