My big question--aside from how the book sells, which obviously you can't say for sure yet, though I wish you all the best--is whether that marketing plan is an actual marketing plan. I.e., what access does the publisher give you that you couldn't have for yourself? What a marketing plan is not is setting up an Amazon page, social media pages, and a blast on the newsletter they are very, very eager to get me to sign up for. Where are they sending ARCs? Do they have a catalogue (not thatI can find)? Do they send press releases to literary outlets and trade publications? Do they get books stocked by libraries and stores?
That's the stuff that will sell books. Not social media. None of those things above require much in the way of funds, just expertise. The focus on funds makes me worry they don't know enough to know that large-scale book advertising isn't particularly effective for small press books.
But, given the founder, Shayne, is also the co-founder of Machovi Productions, a PR/content company specializing in graphic design and "viral email marketing" (that's PR-lingo for spam, folks), my hopes would not be high that Ms. Leighton has any idea at all how to promote effectively, let alone market a book (that is, how to get a book to its market). The Machovi email marketing service page actually lists forum spamming as an effective way to grow an email list. Egads.
There is a certain amount of promotion an author might do on social media, with some help from a publisher. Giveaways, etc., sure. Without a strong marketing foundation, that won't matter beyond a handful of sales to friends and acquaintances. The question that marketing plan needs to answer is "how are people who don't know me and don't care about me going to find out about this book?" If the answer amounts to any form of "they'll see a social media post/ad/widget" then ask yourself when was the last time you bought a book because you saw a random Facebook ad?
Just for fun, I plugged a couple of Parliament House's books into Amazon. It's curious--there are some quite decent sales for some of their recent titles, at least going by Amazon (which does tend to have a recency bias). What caught me, though, is that some of their titles have next to no reviews at all and and zero sales while others have loads. My guess, based on the language in their sub guidelines, is that some of their authors are doing a really great job self-promoting, reaching out to indie book bloggers and getting reviews. And indeed, most of their blurbs are either from the book's editor (!!!!) or from indie blogs. There's nothing wrong with that as a sales strategy if it's working, but I'm also not totally convinced it's a strategy an effective self-publisher couldn't use on her own while taking in a much larger cut of likely the same sales.
The question with small presses should always, always be "what can this press do for its royalty cut that I can't do myself?" Responsiveness and friendliness is great, and I wish Lakini all the best, but this is a business and I don't care how nice they are, I care what they bring to the negotiating table.
(Also, in the curiouser and curiouser category, one of PH's recent publications is also published by--and indeed still available on--our good friends Inkitt, the prolific spammy display site. So kinda curious to know how Parliament House handles rights, as indeed why would anyone buy the book when it's available for free on Inkitt, notwithstanding Inkitt having plagiarized it, which I'm not willing to rule out?)